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Optimizing crop management to boost maize production using modeling approach

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  • Creating models can help improve agricultural production by finding the best ways to use resources. This research assessed maize production in three areas (Bardsir, Jiroft, and Erzuye) within Kerman province in the southeast of Iran with an arid and semi-arid climate by conducting long-term simulation experiments (2000−2019) for three sowing windows (early, common, and late) and three irrigation treatments (11, 13, and 15 times) using the APSIM model. The APSIM model was adjusted and tested to simulate the biological, grain yield, and phenological characteristics of the SC 704 maize hybrid under various nitrogen amounts (0, 92, and 368 kg·ha−1) for 2020 and 2021. The model's accuracy in predicting grain yield was 11.23% during calibration and 13.21% during validation. For total dry matter, the model's accuracy was 14.8% during calibration and 13.9% during validation. Additionally, the model accurately predicted the timing of plant development, particularly the number of days until maturity. The model's accuracy in simulating days to flowering and days to maturity was consistently less than 10% and 5%, respectively. The present findings revealed that Bardsir produced the most maize (8,317 kg·ha−1), while Jiroft yielded the least (4,735 kg·ha−1). Among the different planting times, late planting resulted in the highest yield (8,529 kg·ha−1). In terms of irrigation, applying water 15 times produced the most maize (6,317 kg·ha−1), followed by 13 times (5,919 kg·ha−1), and 11 times (5,671 kg·ha−1). In all the regions studied, the best maize production (8,872.8 kg·ha−1) was achieved by planting late and irrigating 15 times. Overall, farmers can increase maize yield by delaying planting by 20 d to avoid high temperatures during the flowering stage and by irrigating their crops 15 times throughout the growing season.
  • The intestinal mucosal barrier is composed of epithelial cells and intercellular connections, which can effectively regulate the transportation of large molecules in the intestinal lumen, and prevent microorganisms, harmful solutes, toxins, and intraluminal antigens from entering bodies[1]. Mucosal barrier factors such as trefoil factor (TFF) family, diamine oxidase (DAO), and transform growth factor-ɑ (TGF-α) have protective and restorative effects on intestinal mucosal integrity, which are synthesized and secreted by intestinal mucosa[24]. The damage to intestinal barrier function can cause the invasion of antigens and bacteria in the lumen, and eventually lead to intestinal diseases, including diarrhea, inflammatory bowel disease (IBD), and Crohn's disease[57].

    The Notch signaling pathway plays a crucial role in a series of cellular processes, including proliferation, differentiation, development, migration, and apoptosis. Research suggests that the Notch signaling pathway is involved in intestinal development, and it can be connected to intestinal cell lineage specification[8]. Furthermore, the Notch signaling pathway can regulate intestinal stem cells, CD4+T cells, innate lymphoid cells, macrophages, and intestinal microbiota, and intervene in the intestinal mucosal barriers in cases of ulcerative colitis[9]. The activated Notch signaling pathway can suppress the goblet cells differentiation and mucus secretion, which would result in the disruption of the intestinal mucosal barrier[10]. In addition, the absence of the Notch signaling pathway would cause the dysfunction of tight junctions and adherens junctions of intestinal mucosa, which could lead to increased permeability of epithelial cells and exposure of luminal contents to the immune system and inflammation[11]. Phytochemicals, such as cucurbitacin, honokiol and quercetin have been reported to have therapeutic effects on intestinal diseases by targeting the Notch signaling pathway[1214].

    Plant-based diets rich in phytochemicals, such as phenolics, anthocyanins, and vitamins, have been related to the prevention of human diseases[15]. Anthocyanins belong to a subclass of flavonoids, and are mainly in the form of different anthocyanin combined with glucose, galactose, and arabinose[16]. The physiological action of anthocyanins, such as antioxidant activity, anti-inflammation, and anti-obesity effects have been widely reported[17,18]. M3G is found naturally in plants and is reported to be the most common anthocyanin in different blueberry varieties[19,20]. Previous researchers reported that M3G from blueberry suppressed the growth and metastasis potential of hepatocellular carcinoma cells, modulated gut microbial dysbiosis, and protected TNF-α induced inflammatory response injury in vascular endothelial cells[2123]. Anthocyanins with diverse molecular structures and from different dietary sources are bioavailable at diet-relevant dosage rates, and anthocyanins from berry fruit are absorbed and excreted by both humans and rats[24]. Studies have shown that anthocyanins have a protective effect on intestinal barrier damage by regulating gut microbiota, tight junction (TJ) protein expression, and secretion of MUC2[2527]. In addition to physiological indicators related to the intestinal barrier, the regulation of the Notch signaling pathway was involved in this study. Therefore, it is speculated that M3G could improve the colonic mucosal barrier function via the Notch signaling pathway.

    To prove this hypothesis, the effects of M3G on the colonic mucosal barrier function were investigated in DSS-induced colitis mice. The pathological morphology of the colon tissue, markers of intestinal physical barrier function and immune barrier function and the Notch signaling pathway were evaluated to reveal the mechanism of M3G in improving colonic mucosal barrier function. The results are expected to lay the foundation for the utilization of anthocyanins as a promising natural product for improving intestinal diseases.

    M3G (CAS: 30113-37-2) used in this study was purchased from Xinyi Science and Technology Instrument Business Department, Baoji, Shanxi, China (HPLC ≥ 98%).

    Five-week-old male C57BL/6J mice (Wanlei Bio Co., Ltd., Shenyang, Liaoning, China) weighing 16−18 g were housed and given AIN-93M diet (Wanlei Bio Co., Ltd., Shenyang, Liaoning, China) feeding. The animal experiment was carried out according to the guidelines of the Standards for Laboratory Animals of China (GB 14922-94, GB 14923-94, and GB/T 14925-94) and the Ethics Committee of Shenyang Agricultural University (IACUC Issue No.: 2023022401). All animal housing and experiments were conducted in strict accordance with the institutional guidelines for the care and use of laboratory animals.

    After acclimating to the breeding environment for one week, the mice were randomly divided into two groups: control group (CG group, n = 6) and model group (n = 12). On days 1−7, the mice of the model group were given 2.5% DSS (CAS: 9011-18-1) dissolved in drinking water, while the mice of the CG group were given the same volume of drinking water as the model group. On days 8−14, mice of the model group were randomly divided into two equal groups (n = 6): DSS group and M3G group. The mice of the CG and DSS groups were administered intragastrically via drinking water, and the mice of the M3G group were administered intragastrically by M3G (5 mg/kg body weight (BW)/d) dissolved in drinking water, and the liquid volume was controlled to be the same. For all groups of mice, the body weight, food consumption, stool consistency, and bloody stool were measured daily during the experiment. On day 15, mice were sacrificed after a 12 h fast, and the colon tissue samples of the mice were collected. The length of the colon tissue was measured and recorded.

    Colon tissue was embedded with paraffin and then cut into sections. After being dewaxed from paraffin, the tissue was placed in water, and stained with hematoxylin and eosin solution. The stained tissue was dehydrated and sealed for observation. A microscope (BX53, Olympus Co., Ltd., Tokyo, Japan) was used to observe the stained tissue and photographed using 100× magnification. The damage in epithelial cells of colon tissue was evaluated.

    The colon tissue was dewaxed and placed in water after being embedded with paraffin, and then stained with schiff and hematoxylin solution. The stained tissue was dehydrated and sealed for observation. A microscope was used to observe the stained tissue and photographed using 100× magnification. The mucosal thickness and the population of goblet cells of the colon tissue were measured and recorded.

    The expression of MUC2 in colon tissue was detected by RT-PCR. Total RNA was extracted from colon tissue, and the concentration was determined using an ultraviolet spectrophotometer (Thermo Fisher Scientific, Waltham, MA, USA). The single-stranded cDNA of the extracted RNA (0.1 μL) was synthesized using a Transcriptor First Strand cDNA Synthesis Kit (Roche Co., Ltd., Basel, Kanton Basel, Switzerland). ExicylerTM 96 (Bioneer Corporation, Daejeon, Korea) was used to analyze the fluorescence quantitative cDNA. The reaction conditions were as follows: 94 °C for 5 min, 94 °C for 10 s, 60 °C for 20 s, 72 °C for 30 s, then followed by 40 cycles of 72 °C for 2 min 30 s, 40 °C for 1 min 30 s, and then melting from 60 to 94 °C, and incubating at 25 °C for 1−2 min. The primer sequences are shown in Table 1.

    Table 1.  The primer sequences used in the RT-PCR analysis.
    Gene Prime Sequence (5'-3') Size (bp)
    MUC2 Forward TGTGCCTGGCTCTAATA 17
    Reverse AGGTGGGTTCTTCTTCA 17
    β-actin Forward CTGTGCCCATCTACGAGGGCTAT 23
    Reverse TTTGATGTCACGCACGATTTCC 22
     | Show Table
    DownLoad: CSV

    The whole proteins from the colon tissue (200 mg) were extracted using a Whole Cell Lysis Assay kit (BioTeke Co., Ltd., Beijing, China) according to the manufacturer’s protocol. Briefly, colon tissue was cut into pieces, and then mixed with phenylmethylsulfonyl fluorid (PMSF), followed by adding the protein extraction reagents A and B to prepare the tissue homogenate. Protein concentration was then determined using a Bradford Kit (BioTeke Co., Ltd., Beijing, China) according to the manufacturer’s protocol. Proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The membranes were blocked with 5% non-fat dry milk in TBST buffer for 1 h, followed by incubating overnight at 4 °C with the appropriate monoclonal primary antibody (detailed information in Table 2). Then membranes were washed to remove non-bound antibodies, and then incubated with the secondary antibody (goat anti-rabbit immunoglobin G-horseradish peroxidase (IgG-HRP), 1:5000; Wanlei Bio Co., Ltd., Shenyang, Liaoning, China) at 37 °C for 45 min. The enhanced chemiluminescence (ECL) western blotting detection reagent (Wanlei Bio Co., Ltd., Shenyang, Liaoning, China) was used to detect the protein bands, and then the protein bands were visualized by a Gel Imaging System (Beijing Liuyi Biotechnology Co., Ltd., Beijing, China).

    Table 2.  Details of the primary antibodies used in the experiment.
    Primary antibody Dilution ratio Manufacturer
    Claudin-1 1:500 Wanlei Bio Co., Ltd.
    Occludin 1:500 Wanlei Bio Co., Ltd.
    ZO-1 1:500 Wanlei Bio Co., Ltd.
    iFABP 1:1000 ABclonal Technology Co., Ltd.
    DLL1 1:500 Wanlei Bio Co., Ltd.
    DLL4 1:1000 ABclonal Technology Co., Ltd.
    Notch1 1:500 Wanlei Bio Co., Ltd.
    NICD 1:1000 Affinity Biosciences Co., Ltd.
    Hes1 1:1000 ABclonal Technology Co., Ltd.
    TFF3 1:1000 Affinity Biosciences Co., Ltd.
    β-actin 1:1000 Wanlei Bio Co., Ltd.
     | Show Table
    DownLoad: CSV

    The level of SIgA in colon tissue was detected by SIgA ELISA kit (Model number: EM1362, Wuhan Fine Biotech Co., Ltd., Wuhan, Hubei, China). The experiment was carried out according to the ELISA kit instructions.

    CD4+T (CD3+CD4+) cells and CD8+T (CD3+CD8+) cells in colonic lamina propria monocytes (LPMC) were detected by FCM. The colonic epithelial cells were isolated by adding digestive solution to the colon tissue. After digestion, screening, re-suspension precipitation, and centrifugation, the precipitate was collected as colonic LPMC. Labeled antibodies were added to the flow tube and incubated according to the instructions. After washing with phosphate buffered saline (PBS), the cells were re-suspended in PBS solution. The CD4+T (CD3+CD4+) cells and CD8+T (CD3+CD8+) cells were detected by flow cytometric (Agilent Technologies, Inc., Santa Clara, CA, USA).

    Data are expressed as mean ± standard deviation (SD) based on six replicates. Differences between two groups were assessed using Student's t tests. The results were considered statistically significant at p < 0.05. Data were analyzed using Graph Pad Prism 8.0 (Graph Pad Software, San Diego, CA, USA) and SPSS 17.0 (IBM Corporation, Armonk, NY, USA).

    The body weight of mice was monitored daily during the experimental period. As shown in Fig. 1a, after being fed with DSS for 7 d, the body weight of the mice in the DSS group was reduced significantly (p < 0.01) compared with that of the CG group. While the body weight of the mice in the M3G group was increased, and exhibited significantly higher (p < 0.01) body weight gain compared with the DSS group. The DAI score of the mice in the DSS group was significantly higher (p < 0.01) than that of the CG group, but M3G supplementation significantly lowered (p < 0.01) the DAI score (Fig. 1b), which demonstrates that the DSS-induced mice colitis model was established successfully and M3G inhibited colon tissue damage in DSS-fed mice. Compared with the CG group, the food intake of the mice fed with DSS was significantly reduced (p < 0.01), and M3G supplementation significantly increased (p < 0.05) the food intake (Fig. 1c).

    Figure 1.  Effect of M3G on body weight gain, DAI score, and food intake in mice. (a) Body weight gain. (b) DAI score (Fecal consistency: 0 = normal, 1 = semi-formed, 2 = soft stool, 3 = diarrhea or watery stool; bloody stool: 0 = occult blood negative, 1 = occult blood positive, 2 = visible bloody stool, 3 = massive hemorrhage; weight loss: 0 = 0%, 1 = 1%−5 %, 2 = 6%−10% ; 3 = 11%−15% reduction). (c) Food intake. Results are expressed as the mean ± SD (n = 6). * p < 0.05 and ** p < 0.01 indicate significant differences between two groups.

    Representative HE and PAS-stained sections of the colon are shown in Fig. 2a & b. The morphology of colon tissue in the CG group did not exhibit any damage, while damage in epithelial cells and goblet cells, inflammatory cells infiltration, and separation of the muscle layer and mucosal muscle layer were observed in the DSS group. The above damage to the tissue was changed for the better by M3G supplementation, with only small levels of damage in epithelial cells and goblet cells, inflammatory cell infiltration, and separation of the muscle layer and mucosal muscle layer compared to that in the CG group.

    Figure 2.  Effect of M3G on the pathological morphology of colon tissue. (a) HE staining of colon tissue. Original magnifications: 100×. (b) PAS staining of colon tissue. Original magnifications: 100×. (c) The damage score of colon tissue. (1) Epithelial cell damage: 0 = normal morphology; 1 = regional destruction of the epithelial surface; 2 = diffuse epithelial destruction and/or mucosal ulcers involving submucosa; 3 = severe epithelial damage. (2) Inflammatory cell infiltration: 0 = no infiltration or less than 5 cells; 1 = mild infiltration of the inherent layer; 2 = moderate infiltration of the muscular mucosa; 3 = high infiltration of the muscular mucosa; 4 = severe infiltration involving submucosa. (3) Separation of muscle layer and mucosal muscle layer: 0 = normal; 1 = moderate; 2 = severe. (4) Goblet cell depletion: 0 = no depletion; 1 = presence of disordered goblet cells; 2 = 1 to 3 regions without goblet cells; 3 = more than 3 regions without goblet cells; 4 = complete depletion of goblet cells. (d) The colon length. (e) The mucosal thickness of colon tissue. (f) Number of goblet cells in colon tissue. Results are expressed as the mean ± SD (n = 6). * p < 0.05 and ** p < 0.01 indicate significant differences between two groups.

    HE score was calculated to evaluate the degree of colon tissue damage. The HE score in the DSS group was significantly higher (p < 0.01) than that in the CG group. Supplementation of M3G significantly reduced (p < 0.01) the score, which decreased by almost 50% of that in the DSS group (Fig. 2c). The colon length in the DSS group was significantly lower (p < 0.01) than that in the CG group, which was significantly increased (p < 0.01) by M3G supplementation (Fig. 2d). The mucosal thickness and the number of goblet cells of the colon tissue were determined by PAS staining. Compared with the CG group, the mucosal thickness and the number of goblet cells of the colon tissue were significantly decreased (p < 0.01) in the DSS group, but those were significantly increased (p < 0.01) in the M3G group (Fig. 2e & f). These results suggest that M3G supplementation can decrease the pathological damage in the colon tissue induced by DSS.

    The mRNA expression level of MUC2 in the colonic mucosa tissue was determined. Compared with the CG group, DSS significantly decreased (p < 0.01) the mRNA level of MUC2, but this effect was significantly suppressed (p < 0.01) by M3G supplementation (Fig. 3a). The protein levels of claudin-1, occludin, ZO-1, iFABP, and TFF3 in the colon tissue were subsequently assessed. The protein expression levels of claudin-1, occludin, and ZO-1 in the DSS group were significantly lower than those in the CG group (p < 0.01). M3G supplementation significantly inhibited (p < 0.01) the reduction in the expression of these proteins (Fig. 3bd). Regarding the protein expression level of iFABP, it was significantly higher (p < 0.01) in the DSS group than that in the CG group. M3G supplementation significantly decreased (p < 0.01) iFABP expression level compared with the DSS group (Fig. 3e). The protein expression level of TFF3 was significantly higher (p < 0.01) in the DSS group than that in the CG group. However, M3G supplementation significantly intensified (p < 0.01) the increase of TFF3 expression compared with the DSS group (Fig. 3f). These results indicate that M3G can regulate colonic epithelial barrier function.

    Figure 3.  Effects of M3G on the colonic epithelial barrier disruption. (a) The mRNA expression level of MUC2. (b) The protein expression level of claudin-1. (c) The protein expression level of occludin. (d) The protein expression level of ZO-1. (e) The protein expression level of iFABP. (f) The protein expression level of TFF3. Results are expressed as the mean ± SD (n = 6). * p < 0.05 and ** p < 0.01 indicate significant differences between two groups.

    The content of CD4+T (CD3+CD4+) and CD8+T (CD3+CD8+) cells in colonic LPMC of mice in each group were detected by FCM as shown in Fig. 4 and Supplemental Fig. S1. Compared with the CG group, the percentages of CD4+T (CD3+CD4+) and CD8+T (CD3+CD8+) cells in the DSS group were significantly increased (p < 0.01), and those were significantly decreased (p < 0.05) after M3G supplementation (Fig. 4a & b). SIgA was measured as an indicator of immune barrier function in the colon tissue. The level of SIgA in the DSS group was significantly lower (p < 0.01) than that in the CG group. Supplementation of M3G significantly raised (p < 0.01) the level of SIgA (Fig. 4c). These results indicate that M3G can improve the colonic immune dysfunction induced by DSS.

    Figure 4.  Effect of M3G on the colonic immune barrier function. (a) The percentage of CD4+T (CD3+CD4+) cells in the colon tissue. (b) The percentage of CD8+T (CD3+CD8+) cells in the colon tissue. (c) The level of SIgA in the colonic mucosal tissue. Results are expressed as the mean ± SD (n = 6). * p < 0.05 and ** p < 0.01 indicate significant differences between two groups.

    Subsequently, the protein expression levels of Notch1, NICD, DLL4, DLL1, and Hes1 in the colon tissue were measured (Fig. 5). DSS significantly up-regulated (p < 0.01) these protein expression levels compared with the CG group. M3G supplementation significantly (p < 0.01) down-regulated the protein expression levels of Notch1, NICD, DLL4, DLL1, and Hes1 in comparison with the DSS group. The results indicate that M3G can inhibit the over-activation of the Notch signaling pathway.

    Figure 5.  Effects of M3G on the protein expression levels of Notch1, NICD, DLL4, DLL1, and Hes1 in the colon tissue. (a) The protein expression level of Notch1. (b) The protein expression level of NICD. (c) The protein expression level of DLL4. (d) The protein expression level of DLL1. (e) The protein expression level of Hes1. Results are expressed as the mean ± SD (n = 6). * p < 0.05 and ** p < 0.01 indicate significant differences between two groups.

    To explain the relationships between them, the Spearman r correlations between biomarkers and the Notch signaling pathway were analyzed, and represented using a heatmap. As shown in Fig. 6, colon length, food intake, ZO-1, number of goblet, MUC2, SIgA, claudin-1, occludin, body weight gain, and mucosal thickness were significantly (p < 0.01 or p < 0.05) positively correlated with Notch1, NICD, DLL4, DLL1, and Hes1. Conversely, HE score, iFABP, DAI score, CD4+T, and CD8+T were significantly (p < 0.01) negatively correlated with Notch1, NICD, DLL4, DLL1 and Hes1. In particular, TFF3 was only significantly (p < 0.05) positively correlated with DLL1, and Hes1. The results indicate that M3G may ameliorate the colonic mucosal barrier dysfunction via modulation of the Notch signaling pathway.

    Figure 6.  Heatmap of the Spearman r correlations between biomarkers and the Notch signaling pathway. * p < 0.05 and ** p < 0.01 indicate significant differences between two groups.

    Within the last five years, special attention is being paid to the therapeutic effects of anthocyanins. The recent studies could give evidence to prove the therapeutic potential of anthocyanins from different sources against various diseases via in vitro, in vivo, and epidemiological experiments[28]. The anthocyanin supplementation has been demonstrated to have positive effects on intestinal health[29]. The intestinal barrier is one of the crucial factors which can affect intestinal health and normal intestinal barrier function not only maintains intestinal health but also protects overall health by protecting the body from intestine injury, pathogen infection, and disease occurrence[30]. The disruption of intestinal barrier integrity is regarded as an important factor leading to IBD, obesity, and metabolic disorders[3133]. In this study, the effects of M3G on regulating the colonic physical barrier function and colonic immune barrier function in DSS-induced colitis mice were explored.

    M3G supplementation reduced the DAI score and the HE score of colon tissue, and restored colon length, mucosal thickness, and the number of goblet cells in the colon tissue, indicating that M3G can alleviate DSS-induced colon tissue damage and colitis symptoms in mice. The DAI score was developed as a simplified clinical colitis activity index to assess the severity of colitis[34]. Zhao et al. have found that black rice anthocyanin-rich extract can significantly decrease the DAI and HE scores of colon tissue in DSS-induced colitis mice[35]. Intestinal goblet cells are mainly differentiated from multipotential stem cells. Intestinal stem cells were located at the base of the crypt and distributed in intestinal mucosal epithelial cells, composing around 50% of colon epithelial cells[36]. The mucus layer is formed by goblet cell secretion, it separates the intestinal epithelium from the intestinal lumen, thereby preventing the invasion of pathogenic microorganisms and the translocation of intestinal microbiota[37]. The results suggested that M3G might repair the colonic mucosa by increasing the number of goblet cells.

    MUC2 is the most abundant mucin secreted by goblet cells of the colon, goblet cells, and MUC2 play important roles in maintaining and protecting the intestinal mucosal barrier[38]. M3G supplementation restored the level of MUC2 by nearly double that of the DSS group. Claudin-1, occludin, and ZO-1 are TJ proteins, which is an important component of the intestinal physical barrier[39]. M3G supplementation mitigated the down-regulation of claudin-1, occludin, and ZO-1 in DSS-induced colitis mice. Wang et al. have found that Lonicera caerulea polyphenols can increase the expression levels of occludin in HFD rats[40]. Chen et al. have found that purple-red rice anthocyanins alleviated intestinal barrier dysfunction in cyclophosphamide-induced mice by up-regulating the expression of tight junction proteins[41]. iFABP can serve as a biomarker of small bowel damage in coeliac disease and Crohn's disease, and supplementation of M3G down-regulated the expression level of iFABP in colon tissue[42]. It has been reported that TFF3 alleviated the intestinal barrier function by reducing the expression of TLR4 in rats with nonalcoholic steatohepatitis, and supplementation of M3G increased the expression level of TFF3 in this research[43]. Although the effect of M3G on epithelial TJ proteins and other related proteins were limited, the beneficial effect of M3G on the colonic mucosal barrier function was supported by histological evaluation.

    The intestinal immune barrier is composed of intestinal mucosal lymphoid tissue and intestinal plasma cell secreted antibodies. Inflammatory damage in acute colitis influences the gut microbiota, epithelial barrier, and immune function in subsequent colitis[44]. Fructose can influence colon barrier function by regulating some main physical, immune, and biological factors in rats[45]. SIgA, CD4+T cells, and CD8+T cells play important roles in the functioning of the human immune system. The results indicated that M3G supplementation can maintain the colonic immune barrier function by modulating the level of SIgA, and the percentages of CD4+T cells and CD8+T cells of colon tissue.

    Notch signaling pathways are important for the maintenance of intestinal epithelial barrier integrity, and its abnormal activation is related to IBD and colon cancer[46]. Among the four Notch receptors in mammals, the most scattered in the intestine is Notch1[47]. NICD is the active form of the Notch receptor, NICD enters the nucleus, binds to the recruitment co-activator transcription complex, and then combines with the Hes gene to regulate the fate of cells[48,49]. DLL1 and DLL4 can serve as ligands for Notch signaling receptors[50]. Lin et al. found that qingbai decoction had beneficial effects on the mucus layer and mechanical barrier of DSS-induced colitis by inhibiting Notch signaling[51]. Supplementation with M3G significantly down-regulated Notch1, NICD, DLL4, DLL1, and Hes1 expression levels in the colon tissue, and there is a significant correlation between biomarkers and Notch signaling pathway-related proteins, suggesting that M3G might sustain the colonic barrier function via inhibiting the Notch signaling pathway.

    The present results showed that M3G exerted an improvement effect on the colonic mucosal barrier (physical barrier and immune barrier) function in DSS-induced colitis mice. The positive impact of M3G on the colonic mucosal barrier function may be ascribed to the modulation of permeability, stability, and integrity of the colonic mucosa by down-regulating the Notch signaling pathway. The results provide theoretical support for anthocyanins as the raw materials of functional products related to intestinal health. However, this study also has limitations, such as lacking intensive research on the effect mechanisms through cell experiments. Therefore, intensive research and clinical tests are the future direction.

    The authors confirm contribution to the paper as follows: study conception and design: Zhang C, Jiao X; data collection: Zhang L; analysis and interpretation of results: Zhang C, Zhang L, Zhang B, Zhang Y; draft manuscript preparation: Zhang C, Wang Y, Tan H, Li L, Jiao X. All authors reviewed the results and approved the final version of the manuscript.

    The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

    We would like to thank the Liaoning Provincial Department of Education Project - General Project (LJKMZ20221060).

  • The authors declare that they have no conflict of interest.

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    Amiri S, Zakeri N, Yousefi T. 2024. Optimizing crop management to boost maize production using modeling approach. Circular Agricultural Systems 4: e017 doi: 10.48130/cas-0024-0017
    Amiri S, Zakeri N, Yousefi T. 2024. Optimizing crop management to boost maize production using modeling approach. Circular Agricultural Systems 4: e017 doi: 10.48130/cas-0024-0017

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Optimizing crop management to boost maize production using modeling approach

Circular Agricultural Systems  4 Article number: e017  (2024)  |  Cite this article

Abstract: Creating models can help improve agricultural production by finding the best ways to use resources. This research assessed maize production in three areas (Bardsir, Jiroft, and Erzuye) within Kerman province in the southeast of Iran with an arid and semi-arid climate by conducting long-term simulation experiments (2000−2019) for three sowing windows (early, common, and late) and three irrigation treatments (11, 13, and 15 times) using the APSIM model. The APSIM model was adjusted and tested to simulate the biological, grain yield, and phenological characteristics of the SC 704 maize hybrid under various nitrogen amounts (0, 92, and 368 kg·ha−1) for 2020 and 2021. The model's accuracy in predicting grain yield was 11.23% during calibration and 13.21% during validation. For total dry matter, the model's accuracy was 14.8% during calibration and 13.9% during validation. Additionally, the model accurately predicted the timing of plant development, particularly the number of days until maturity. The model's accuracy in simulating days to flowering and days to maturity was consistently less than 10% and 5%, respectively. The present findings revealed that Bardsir produced the most maize (8,317 kg·ha−1), while Jiroft yielded the least (4,735 kg·ha−1). Among the different planting times, late planting resulted in the highest yield (8,529 kg·ha−1). In terms of irrigation, applying water 15 times produced the most maize (6,317 kg·ha−1), followed by 13 times (5,919 kg·ha−1), and 11 times (5,671 kg·ha−1). In all the regions studied, the best maize production (8,872.8 kg·ha−1) was achieved by planting late and irrigating 15 times. Overall, farmers can increase maize yield by delaying planting by 20 d to avoid high temperatures during the flowering stage and by irrigating their crops 15 times throughout the growing season.

    • Agriculture, the main economic activity in many developing nations, is predicted to be required to feed the estimated nine billion one hundred million people by 2050[1]. Considering the environmental concerns, soil preservation, and the increasing water shortage, especially in dry and semi-dry areas like Iran, it's essential to use water and fertilizer wisely to reduce harm and increase profit[2]. Maize, a member of the grass family, is a major cereal crop grown in both tropical and temperate areas around the globe[3]. The total area planted with grain maize in Iran is approximately 159,106 ha, while the area planted with fodder maize is around 385,881 ha. The average yield for grain maize is about 7,139 kg·ha−1. In Kerman province, the area cultivated for grain maize is 35,846 ha, of which 23,865 ha are in the southern part and 11,981 ha are in the province itself. The province also has about 14,254 ha of fodder maize cultivation area, with 9,223 ha in the south and 5,031 ha in Kerman province. The average maize yield in Kerman province is 7,283 kg·ha−1. Overall, Kerman province ranks third in maize production in Iran, following Khuzestan and Fars provinces[4]. Irrigation can be categorized based on the plant type, soil, and weather conditions. There are two main types: full irrigation and deficit irrigation. Full irrigation has been shown to increase maize yield, leading to both higher production and more consistent yields[5]. The amount of water needed by maize plants changes throughout their growth. To avoid water stress during important growth phases, it is suggested to use extra irrigation and plant early. These methods can improve both production and the efficient use of water[6]. Additionally, a study in northeast China examined how irrigation and planting timing affected maize yield. The results showed that irrigating between late June and early July increased grain yield by 35% compared to relying solely on rainfall and planting later[7].

      There are several ways to investigate different farming practices. Field experiments are useful for studying how various factors affect plant growth. However, these experiments can take a long time and be expensive. Moreover, field experiments have limitations, such as being only relevant to specific locations, being relatively short, and being unable to examine many different treatments and situations. Crop simulation models are highly valuable and impactful in this field, offering numerous practical applications. They play a crucial role, particularly in situations where resource constraints pose challenges to agricultural research[1]. These models are the only method to combine research findings from studies conducted in different locations[8]. The Agricultural Production Systems Simulator (APSIM) is a process-oriented simulation model for agricultural plants and systems[9]. It effectively simulates the economic output of various crops, pastures, and trees by considering factors such as climate, soil conditions, and management practices. Additionally, APSIM can simulate different rotation systems[10]. The APSIM model, which was developed by Australian researchers, is highly effective in simulating crop growth and yield. It specifically focuses on the daily growth and development of maize, taking into account various influential factors such as weather conditions (temperature, rainfall, and radiation), soil properties (soil water and soil nitrogen), genetic parameters, and crop management inputs[11]. MacCarthy et al.[9] examined the impact of plant residue management on sorghum yield over 30 years using the APSIM model. Their findings indicated that as soil organic matter decreases, sorghum grain yield gradually declines. The APSIM model effectively simulated the influence of both organic and chemical fertilizers on plant growth in their experiment. Additionally, the results demonstrated that returning plant residues back to the soil could potentially reduce the required amount of nitrogen fertilizer by 50%. In a study conducted in Ghana, the APSIM model was utilized to predict the response of sorghum's total dry matter to nitrogen and phosphorus fertilizers under two distinct management systems. The model successfully evaluated the total dry matter with a coefficient of determination R2 = 0.86[12]. Similarly, researchers in Kenya employed the APSIM model to evaluate maize and bean production in various phosphorus and chemical fertilizers treatments. The comparison between the observed and simulated values showed R2 = 0.79 and 0.69 for grain yield and total dry matter produced by common bean, respectively. For maize, the corresponding values were 0.82 and 0.74[13]. The purpose of this study was to evaluate the APSIM model's ability to accurately simulate the growth and yield of grain maize in Kerman province, considering the importance of grain maize production and the need to improve crop efficiency given Iran's limited resources. By utilizing a modeling approach, the study aimed to assess management scenarios like planting windows and irrigation management for maize production.

    • This study was conducted in three different regions: Bardsir, which has a temperate to cold climate; Jiroft and Orzueeyeh, both of which have hot and dry climates. The purpose of this research was to simulate crop management, specifically focusing on planting windows and irrigation, to evaluate their impact on grain yield. The ultimate goal was to identify the optimal management scenario using a simulation-based approach. Details regarding the climate and soil characteristics of the study areas can be found in Tables 1 & 2.

      Table 1.  Climatic and geomorphological attributes of the regions.

      Region Longitude Latitude Elevation (m) Mean annual temperature (°C) Mean cumulative precipitation (mm)
      Bardsir 56.57 29.93 2044 14.5 165
      Orzueeyeh 56.36 28.45 1053 23.3 122.3
      Jiroft 57.73 28.67 720 25.1 176.2

      Table 2.  Pedological attributes of the regions.

      Attributes Region
      Bardsir Orzueeyeh Jiroft
      Soil type Loam sand Loam Loam sand
      Available soil water (mm) 126 113 115
      Bulk density (g·cm−3) 1.4 1.62 1.52
      pH 7.9 7.9 8
      Electrical conductivity (dS·m−1) 2 1.9 1.2
      Organic matter (%) 0.2 0.2 0.2
      Nitrate (mg·L−1) 8.2 79.4 73.1
      Ammonium (mg·L−1) 2.13 2.26 2.76
      Phosphorous (ppm) 4 4 10
      Potassium (ppm) 120 180 200
    • The APSIM model was employed in this study to simulate grain yield. This model consists of 11 growth stages and 10 phases, representing the time intervals between these stages. The initiation of each phase is determined by cumulative temperature time, except the period from planting to germination, which varies based on soil moisture. The duration of the phase between emergence and the onset of flowering remains constant for each cultivar, often referred to as the vegetative or juvenile phase. However, the rate of development during the transition from the juvenile phase to flowering is influenced by day length, particularly if the cultivar is sensitive to photoperiod[14,15].

      The model incorporates separate modules to simulate soil, water, and nitrogen relationships. In the water sub-model, the daily water demand of the plant (transpiration demand) is simulated using the method provided by Sinclair[12] and Monteith[16]. According to this method, the plant's water demand is determined by its daily growth rate, vapor pressure deficiency, and transpiration efficiency coefficient. Additionally, the APSIM model's nitrogen simulation encompasses various processes such as nitrogen absorption, transport, accumulation in plants, nitrogen leaching, nitrification, denitrification, and other nitrogen-related processes in the soil. These processes are simulated daily for each soil layer. Similar to water absorption, the estimation of nitrogen absorption by plants is based on supply and demand.

      To simulate, the required data are plant, management, soil, and climate data. The weather data for the model spans from 2000 to 2019 and includes temperature, sunny hours, and rainfall. This data was collected from the synoptic weather stations in three regions: Bardsir, Jiroft, and Orzueeyeh. However, since daily radiation intensity is not regularly recorded at these synoptic stations, the length of sunny hours was used as an estimate for this variable. To calculate radiation, sunshine hours, and Angstrom's linear relationship[17] were employed.

      Rs=(a+bnN)Ra (1)

      Where, Rs represents the daily radiation (MJ·m−2). The variable n denotes the number of hours with sunny weather, while N represents the day length. Additionally, Ra refers to the extraterrestrial radiation. It is important to note that the variables a and b correspond to the locally calibrated Angstrom coefficients specific to different regions within Kerman province[18]. The soil data were collected from various sources, including agricultural research stations, the water and soil department, and soil science laboratories. These data encompassed several physical and chemical characteristics of the experimental field soil. Some of these characteristics include the percentage of clay, silt, and sand in the soil texture, available soil water, bulk density, pH level, cation exchange capacity (CEC), organic carbon content, electrical conductivity (EC), nitrate (mg·L−1), ammonium (mg·L−1), phosphorous (ppm), and potassium (ppm). These collected data were utilized to determine the soil coefficients of the model, such as field capacity and permanent wilting point. Additionally, they were used to estimate the available soil water (mm) (Table 2). The SPAW model, developed by Saxton & Willey[19] was employed to estimate these soil parameters.

      The management data for the study regions included various parameters. These parameters encompassed the planting window, plant density (7 plants m−2), number of irrigations, amount of nitrogen fertilizer, planting row distance (75 cm), type of plowing (common plowing), and seed planting depth (5 cm). To gather this information, a questionnaire was designed and field research was conducted by experts in the studied locations. To obtain the best sowing window and irrigation management, various treatments were evaluated. The planting windows were the common planting date in the study regions, an early planting window that was 20 d before the common planting window, and a late planting window that was 20 d after the common window. The primary purpose of the late planting date was to evaluate the impact of heat stress on yield. For the irrigation treatments, the common irrigation in each area (13 times), deficit irrigation (11 times), and over-irrigation (15 times) were evaluated. Table 3 shows detailed information on the planting windows, irrigation, and nitrogen fertilizer used in each region.

      Table 3.  Common sowing window, number of irrigations, and the quantity of nitrogen fertilizer.

      Location Sowing window Number of
      irrigations
      Nitrogen fertilizer
      (kg N ha−1)
      Bardsir 21-Apr 16 276
      Orzueeyeh 01-Jul 16 260
      Jiroft 21-Jul 16 253
    • The calibration of the model was carried out using an experiment conducted in 2020. The field experiment took place at the Research and Education Center for Agriculture and Natural Resources (30.17° N, 57.04° E) in Kerman province (Iran). The experiment was based on a randomized complete block design with four replications. The SC 704 maize hybrid was evaluated under four nitrogen levels (0, 92, and 368 kg·ha−1). Each plot comprised seven rows, six meters in length, spaced 75 cm apart. The plant density was 7 plants m−2. In the context of model calibration through a systematic trial and error approach, the objective was to minimize the discrepancy between the observed and projected values. Key parameters that significantly affected dry matter accumulation and the duration from sowing to flowering and maturation were adjusted. This iterative process continued until the model's simulated values were closely aligned with the observed data across all experimental treatments. The genetic coefficients for the SC 704 cultivar are presented in Table 4.

      Table 4.  Parameters determined by adjusting the model calibration for SC704 cultivar.

      Parameter Value Unit
      Maximum number of seeds per head 850
      Thermal time from emergence to juvenile stage 270 °Cd
      Seed growth rate 8 mg kernel–1 d–1
      Thermal time from juvenile phase to floral stage 20 °Cd
      Critical photoperiod 1 12.5 h
      Critical photoperiod 2 20 h
    • To enhance the model evaluation, in addition to the 2021 experiment in Kerman, two other experiments were included, which had similar climatic conditions to the experimental area[14,15].

      The 2nd experiment[14] was used to validate the crop in Kerman county (30.17° N, 57.04° E) in Iran. The experiment was a factorial arrangement based on a randomized complete block design (RCBD) with three replications. Four nitrogen rates (0 (control), 92, 220, and 368 kg·ha–1) and two maize hybrids (KSC 704 and Maxima) were included in the study. The mean temperature and cumulative rainfall were 23 °C during the maize growing season. The sowing date was 2 May. Each plot consisted of seven rows of six meters in length and with a spacing of 75 cm. Plant density was 7 plants m–2. The soil texture was loam clay. Cultivars were harvested at their physiological maturity stages.

      The 3rd experiment was also considered to validate the crop model under different irrigation levels. The field experiment was laid out as a split plot-factorial arrangement based on RCBD with three replications in the research field of Shahid Chamran University of Ahvaz, Iran (31.18° N, 48.40° E) during the 2009−2010 growing season. Irrigation was assigned to main plots in three levels 100%, 80%, and 60% of field capacity. Nitrogen fertilizer at three levels 0, 100, and 150 kg N ha–1 and KSC 704 and Maxima was considered as factorial in subplots. The soil texture was clay. The sowing date was 12 May. Each plot included seven rows of six meters in length with a spacing of 75 cm. Plant density was 7 plants m–2.

      Different indices were employed to assess model accuracy. R2, nRMSE[16], and CRM were used[17]. The coefficient of residual mass (CRM) was used to check whether model predictions provided overestimation or underestimation. A negative CRM shows a tendency to overestimate[16]. The nRMSE represents the model's simulation error by giving too much weight to high errors. The model precision is higher when nRMSE approaches zero[17]. R2 ranges between 0 and 1 and the R2 to 1, the more accurate the model.

      nRMSE=ni=1(PiOi)2n×100¯O (2)
      CRM=1ni=1Pini=1Oi (3)

      where, Oi and Pi are measured and simulated values, respectively, and O equals the average measured value.

    • The APSIM model was not able to accurately represent how different amounts of nitrogen fertilizer affected the timing of maize development (Table 5). Changing the amount of nitrogen fertilizer did not impact the model's predictions for how long it took for the maize plants to start flowering and to mature. Moreover, the output of the model under all nitrogen fertilizer (0, 92, and 368 kg·ha–1) was the same for each year (69 and 66, respectively for flowering in 2020, and 129 and 123 in 2021). However, the field experiment showed a significant effect of nitrogen fertilizer on phenological stages, especially the flowering stage (Table 5). Despite some partial underestimation of the model, especially in the validation stage (2021), the model captured phenology, especially days to maturity, with high accuracy, at different fertilizer levels (0, 92, and 368 kg·ha–1). On average, nRMSE for simulating days to flowering was 10%, and the nRMSE for simulating days to maturity was 5% (Table 5).

      Table 5.  Evaluation indices of the APSIM model in simulating days from sowing to flowering and maturity under different nitrogen fertilizer (0, 92, and 368 kg·ha−1) in calibration (2020), and validation (2021) years.

      Treatment Calibration (2020) Validation (2021)
      Observed Simulated Observed Simulated
      Days from sowing to flowering
      0 kg N ha−1 74 69 87 66
      92 kg N ha−1 68 69 80 66
      368 kg N ha−1 69 69 76 66
      nRMSE (%) 2.41 10.17
      CRM (−) 0.018 0.185
      Days from sowing to maturity
      0 kg N ha−1 131 129 135 123
      92 kg N ha−1 128 129 134 123
      368 kg N ha−1 132 129 136 123
      nRMSE (%) 0.95 5.14
      CRM (−) 0.01 0.08

      Gungula et al.[18] using the CERES model evaluated the effect of nitrogen management on the phenology of seven late maize hybrids in Nigeria. Their results showed nitrogen level and days to physiological maturity (R2 = 0.7) in most hybrids. The model predicted silking windows well under high nitrogen levels (90 and 120 kg·ha–1), with a difference of less than two days. Similarly, days to maturity were also simulated accurately for most hybrids under high nitrogen levels, with a difference of less than two days. However, under low nitrogen levels, there were larger differences between the observed and simulated data. They concluded that the CERES-maize model is reliable for predicting maize phenology only under non-limiting nitrogen conditions. To improve the accuracy of phenology prediction in nitrogen-limited soils, they suggested incorporating a nitrogen stress factor into the model. Soler et al.[19] also reported the successful use of the CERES-maize model to simulate the phenology of four grain maize hybrids with different maturity groups in a semi-tropical region in Brazil under irrigated and rainfed cropping systems.

      The simulation of total dry matter for hybrid SC 704 was carried out with high accuracy. The nRMSE for simulating the total dry matter of hybrid SC 704 was 13.8% in the calibration stage and 12.7% in the validation stage (Table 6). There was underestimation (CRM = 0.19) in the prediction of total dry matter in the calibration stage, and overestimation (CRM = 0.18) was observed in the validation stage. The R2 the total dry matter for the calibration and validation stages was 0.98 and 0.89, respectively (Fig. 1a & b).

      Table 6.  Evaluation parameters of model in simulating total dry matter and grain yield of maize SC704 hybrid under the different quantity of nitrogen (0, 92, and 368 kg·ha−1) for calibration (2020), and validation (2021) years.

      TotalCalibration (2020)Validation (2021)
      nRMSE (%)CRM (−)nRMSE (%)CRM (−)
      Dry matter13.770.1912.75−0.18
      Grain yield11.230.1213.21−0.15

      Figure 1. 

      Comparison of the empirically observed and model-simulated dry matter employing the APSIM framework for the SC704 hybrid cultivar, subjected to varying nitrogen levels (0, 92, and 368 kg·ha−1), was conducted in the years 2020 (a) calibration and 2021 (b) validation.

      The APSIM model simulated yield under different nitrogen treatments with high accuracy in both the calibration and validation stages (Figs 2 & 3). The nRMSE of yield was 11.23% and 13.21% in the calibration and validation stages, respectively (Table 6). Furthermore, the model predicted yield with R2 values of 0.96 and 0.89 in the calibration and validation stages, respectively (Figs 2 & 3). Kpongor[10] stated that the model could predict sorghum production in various nitrogen and phosphorus fertilizers under two different management systems in Ghana (R2 = 0.81).

      Figure 2. 

      A comparative analysis of the actual and predicted grain yield utilizing the APSIM model for the SC704 hybrid was conducted under varying nitrogen applications (0, 92, and 368 kg·ha−1) during the year 2020, designated as the calibration year.

      Figure 3. 

      A comparative analysis of the empirically observed and model-predicted grain yield of the SC704 hybrid was conducted utilizing two distinct datasets[14,15] under varying nitrogen applications (0, 92, and 368 kg·ha−1) in the year 2021 (validation) within the Kerman region.

    • The average simulated yield was 6,678 kg·ha−1 (Fig. 4). Across planting windows and irrigation treatments, the maximum and minimum grain yields were observed in Bardsir and Jiroft, respectively, with 8,317 and 4,735 kg·ha−1 (Fig. 4). The results approved that there is high potential to increase maize production in the studied regions. For example, in Bardsir, maize had a longer growth period (145.6 d) and a lower average temperature during the growth period (21.8 °C) (Table 7), which resulted in a higher yield in this region compared to other regions. Generally, with the reduction in growth period, especially the duration of the vegetative growth, maize grain yield decreased.

      Figure 4. 

      Grain productivity in relation to various irrigation regimens (IR11: 11 irrigation instances; IR13: 13 irrigation instances; IR15: 15 irrigation instances), planting periods (early, common, and late), as well as the geographical sites examined (Bardsir, Jiroft, and Orzueeyeh). The dimensions of the box plots illustrate the variations in the projected grain yield across different years (2000−2019).

      Table 7.  Average temperature for growing season, days to maturity, and average maximum temperature for flowering period under different planting windows (common, early, and late) and regions (2000−2019).

      Region Planting window Average temperature during the growing season (°C) Days to maturity Average maximum temperature for flowering period (°C)
      Bardsir Common 22.3 142 34.5
      Early 22.5 154 33.9
      Late 20.7 141 33.9
      Orzueeyeh Common 28.7 133 38.9
      Early 32.6 129 42.3
      Late 22.5 154 34.4
      Jiroft Common 28.2 130 38.7
      Early 31.8 124 41.3
      Late 21.4 154 33.9

      Across different planting windows, the late planting window outperformed the common and early planting windows in all regions and irrigation treatments. The yield of the late planting window was 8,529 kg·ha−1, which was 26% higher than the common planting window and 200% higher than the early planting window, respectively (Fig. 4). The late planting window causes flowering at lower temperatures, which reduces the mean maximum temperature during the flowering phase of maize up to 8% and 13% compared to the common and early planting windows, respectively (Table 7). Many studies have shown that maize is sensitive to very high temperatures, and increasing the temperature can greatly reduce its yield[13]. This yield reduction can be caused by increased respiration, reduced photosynthesis, a shortened crop growth period, and especially reduced pollen grain fertility and sterility.

      In maize, the maximum temperature above 36 °C causes pollen grains to become sterile, preventing seed formation. This effect can be seen in Fig. 4 and in the early planting windows in the Jiroft and Orzueeyeh regions, where the maximum high temperatures caused no seed formation in maize (Fig. 4 & Table 7). Overall, increasing temperature led to a reduction in the number of maize pollen grains by reducing their fertility. Therefore, the increase in temperature had the greatest effect on the flowering stage of maize and ultimately caused a decrease in the number of seeds and maize yield by reducing the percentage and period of flower fertilization.

      Across the regions and planting window treatments, the highest grain yields were obtained with 6,317, 5,919, and 5,671 kg·ha−1 in treatments of 15, 13, and 11 times of irrigation, respectively (Fig. 4). Among the different interactions in Kerman province, the late planting window with 15 times irrigation had the highest yield, at 8,872 kg·ha−1. Furthermore, considering the region, the greatest yield was recorded in the Bardsir region on the late planting window with 15 times irrigation, at 9,300 kg·ha−1 (Fig. 4). Grain yield depends on the average temperature during the maize growing season. In hot regions, high temperatures can negatively affect yield by shortening the growing season. In cool regions, an increase in temperature can improve the temperature conditions for crop growth[7]. The average temperature during the growing season in Bardsir and on the late planting window was lower than in other regions and on other planting windows (Table 7), which led to higher grain yield. A shorter growing season can shorten the grain filling period and decrease yield[6]. Conversely, a decrease in temperature can increase the growing season period and provide better conditions for crop growth. On average throughout Kerman, the 15 times irrigation treatment and late planting had the highest effect on production (8,872.8 kg·ha−1). Increasing the frequency of irrigation (15 times during the growing season) reduces water stress on the crop and increases grain yield compared to irrigating 11 or 13 times. This level of irrigation, along with late planting, can create optimal conditions for better performance.

    • The present findings showed that the APSIM model was fairly accurate in predicting maize growth and yield in Kerman province. However, the model's main drawback was its inability to accurately reflect how nitrogen deficiency affects plant development. This makes it a valuable tool for estimating crop yields before conducting field experiments, which can save research costs. The present findings suggest that the usual planting times chosen by farmers can reduce their yields. Additionally, many farmers plant maize during a period when extreme temperatures are more likely. To increase their yields, farmers should plant 20 d later than usual and irrigate their crops 15 times during the growing season. To improve maize production, it's recommended to use computer simulations to assess how different types of maize respond to changes in various farming practices like planting density, planting time, watering, and nitrogen fertilizer. These simulations can help farmers make better decisions about how to manage their crops.

    • This research followed all necessary rules and regulations for studying potentially endangered plants. Tehran University reviewed and approved the experiments to make sure they complied with international guidelines on protecting endangered species.

      • The authors confirm contribution to the paper as follows: methodology, evaluation, writing – original draft preparation: Amiri S; writing – review & editing: Zakeri N, Yousefi T. All authors reviewed the results and approved the final version of the manuscript.

      • The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

      • The authors thank the ANRCC of Kerman.

      • The authors declare that they have no conflict of interest.

      • Copyright: © 2024 by the author(s). Published by Maximum Academic Press, Fayetteville, GA. This article is an open access article distributed under Creative Commons Attribution License (CC BY 4.0), visit https://creativecommons.org/licenses/by/4.0/.
    Figure (4)  Table (7) References (19)
  • About this article
    Cite this article
    Amiri S, Zakeri N, Yousefi T. 2024. Optimizing crop management to boost maize production using modeling approach. Circular Agricultural Systems 4: e017 doi: 10.48130/cas-0024-0017
    Amiri S, Zakeri N, Yousefi T. 2024. Optimizing crop management to boost maize production using modeling approach. Circular Agricultural Systems 4: e017 doi: 10.48130/cas-0024-0017

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