Research on the Dynamic Simulation System of Maize Growth

Dynamic simulation system of maize growth is developed by the physiological and ecological model,morphological structure model,computer science and virtual reality technology,to improve the level of precise operation of maize production.The computer graphics algorithms,virtual reality technology,animation design and information integration technology are applied to maize production by this system.establishment of dynamic simulation system of maize growth is conducive to raise level of precise operation in maize production.The system also can assist the relevant production research and testing,to reduce cost and improve efficiency.

Optimizing Parameters of CSM-CERES-Maize Model to Improve Simulation Performance of Maize Growth and Nitrogen Uptake in Northeast China

Crop models can be useful tools ibr optimizing fertilizer management for a targeted crop yield while minimizing nutrient losses. In this paper, the parameters of the decision support system for agrotechnology transfer （DSSAT）-CERES-Maize were optimized using a new method to provide a better simulation of maize （Zea mays L.） growth and N upfake in response to different nitrogen application rates. Field data were collected from a 5 yr field experiment （2006-2010） on a Black soil （Typic hapludoll） in Gongzhuling, Jilin Province, Northeast China. After cultivar calibration, the CERES-Maize model was able to simulate aboveground biomass and crop yield of in the evaluation data set （n-RMSE=5.0-14.6%）, but the model still over-estimated aboveground N uptake （i.e., with E values from -4.4 to -21.3 kg N ha-~）. By analyzing DSSAT equation, N stress coefficient for changes in concentration with growth stage （CTCNP2） is related to N uptake. Further sensitivity analysis of the CTCNP2 showed that the DSSAT model simulated maize nitrogen uptake more precisely after the CTCNP2 coefficient was adjusted to the field site condition. The results indicated that in addition to calibrating 6 coefficients of maize cultivars, radiation use efficiency （RUE）, growing degree days for emergence （GDDE）, N stress coefficient, CTCNP2, and soil fertility factor （SLPF） also need to be calibrated in order to simulate aboveground biomass, yield and N uptake correctly. Independent validation was conducted using 2008-2010 experiments and the good agreement between the simulated and the measured results indicates that the DSSAT CERES-Maize model could be a useful tool for predicting maize production in Northeast China.

Comparative short-term effects of sewage sludge and its biochar on soil properties, maize growth and uptake of nutrients on a tropical clay soil in Zimbabwe

Soil application of biochar from sewage could potentially enhance carbon sequestration and close urban nutrient balances. In sub-Saharan Africa, comparative studies investigating plant growth effect and nutrients uptake on tropical soils amended with sewage sludge and its biochar are very limited. A pot experiment was conducted to investigate the effects of sewage sludge and its biochar on soil chemical properties, maize nutrient and heavy metal uptake, growth and biomass partitioning on a tropical clayey soil. The study compared three organic amendments; sewage sludge （SS）, sludge biochar （SB） and their combination （SS＋SB） to the unamended control and inorganic fertilizers. Organic amendments were applied at a rate of 15 t ha-1 for SS and SB, and 7.5 t ha-1 each for SS and SB. Maize growth, biomass production and nutrient uptake were significantly improved in biochar and sewage sludge amendments compared to the unamended control. Comparable results were observed with F, SS and SS＋SB on maize growth at 49 d of sowing. Maize growth for SB, SS, SS＋SB and F increased by 42, 53, 47, and 49%, respectively compared to the unamended control. Total biomass for SB, SS, SS＋SB, and F increased by 270,428, 329, and 429%, respectively compared with the unamended control. Biochar amendments reduced Pb, Cu and Zn uptakes by about 22% compared with sludge alone treatment in maize plants. However, there is need for future research based on the current pot experiment to determine whether the same results can be produced under field conditions.

Comparison of nitrogen losses by runoff from two different cultivating patterns in sloping farmland with yellow soil during maize growth in Southwest China

The loss of N in farmland is an important cause of agricultural non-point source pollution, which seriously impacts the aquatic environment. A two-year(2017–2018) experiment was conducted to investigate the characteristics of runoff and N losses under different tillage practices. Taking downslope ridge planting and cross ridge planting as the experimental treatments,the characteristics of surface runoff, interflow, and N losses in sloping farmlands with yellow soil were studied throughout the maize growth period. As the rainfall increased, the surface runoff and interflow also increased. The surface runoff and N losses in the surface runoff of downslope ridge planting were significantly higher than those of cross ridge planting. The interflow volumes and N losses in the 0–20 and 20–40 cm soil layers of the cross ridge planting were significantly higher than those of the downslope ridge planting. The total N(TN) losses from surface runoff accounted for 54.95–81.25% of the N losses from all pathways. Therefore, we inferred that surface runoff is the main pathway of N losses. Dissolved total N(DTN) was the main form of N loss under different tillage measures, as it accounted for 55.82–94.41% of the TN losses,and dissolved organic N accounted for 52.81–87.06% of the DTN losses. Thus, we inferred that dissolved N is the main form of N loss. Future research must focus on the prevention and control of the N losses during the maize seedling stage to reduce the environmental pollution caused by ammonium N through runoff.

Improving maize growth and development simulation by integrating temperature compensatory effect under plastic film mulching into the AquaCrop model

Temperature compensatory effect, which quantifies the increase in cumulative air temperature from soil temperature increase caused by mulching, provides an effective method for incorporating soil temperature into crop models. In this study, compensated temperature was integrated into the AquaCrop model to investigate the capability of the compensatory effect to improve assessment of the promotion of maize growth and development by plastic film mulching(PM). A three-year experiment was conducted from2014 to 2016 with two maize varieties(spring and summer) and two mulching conditions(PM and non-mulching(NM)), and the AquaCrop model was employed to reproduce crop growth and yield responses to changes in NM, PM, and compensated PM. A marked difference in soil temperature between NM and PM was observed before 50 days after sowing(DAS) during three growing seasons. During sowing–emergence and emergence–tasseling, the increase in air temperature was proportional to the compensatory coefficient, with spring maize showing a higher compensatory temperature than summer maize. Simulation results for canopy cover(CC) were generally in good agreement with the measurements, whereas predictions of aboveground biomass and grain yield under PM indicated large underestimates from 60 DAS to the end of maturity. Simulations of spring maize biomass and yield showed general increase based on temperature compensation, accompanied by improvement in modeling accuracy, with RMSEs decreasing from 2.5 to 1.6 t ha^(-1)and from 4.1 t to 3.4 t ha^(-1). Improvement in biomass and yield simulation was less pronounced for summer than for spring maize, implying that crops grown during low-temperature periods would benefit more from the compensatory effect. This study demonstrated the effectiveness of the temperature compensatory effect to improve the performance of the AquaCrop model in simulating maize growth under PM practices.

Relationship of Soil Qualities to Maize Growth Under Increasing Phosphorus Supply in Acid Soils of Southern Cameroon

A large array of soil properties influences plant growth response to phosphorus(P) fertilizer input in acid soils. We carried out a pot experiment using three contrasted acid soils from southern Cameroon with the following main objectives:i) to assess the main soil causal factors of different maize(Zea mays L.) growth response to applied P and ii) to statistically model soil quality variation across soil types as well as their relationships to dry matter production. The soils used are classified as Typic Kandiudox(TKO) ,Rhodic Kandiudult(RKU) ,and Typic Kandiudult(TKU) . Analysis of variance,regression,and principal component analyses were used for data analysis and interpretation. Shoot dry matter yield(DMY) was significantly affected by soil type and P rate with no significant interaction. Predicted maximum attainable DMY was lowest in the TKO(26.2 g pot-1) as compared to 35.6 and 36.7 g pot-1 for the RKU and TKU,respectively. Properties that positively influenced DMY were the levels of inorganic NaHCO3-extractable P,individual basic cations(Ca,Mg,and K) ,and pH. Their effects contrasted with those of exchangeable Al and C/N ratio,which significantly depressed DMY. Principal component analysis yielded similar results,identifying 4 orthogonal components,which accounted for 84.7% of the total system variance(TSV) . Principal component 1 was identified as soil nutrient deficiency explaining 35.9% of TSV. This soil quality varied significantly among the studied soils,emerging as the only soil quality which significantly(P < 0.05) correlated with maize growth. The 2nd,3rd,and 4th components were identified as soil organic matter contents,texture,and HCl-extractable P,respectively.

Effects of drip and flood irrigation on carbon dioxide exchange and crop growth in the maize ecosystem in the Hetao Irrigation District,China

Drip irrigation and flood irrigation are major irrigation methods for maize crops in the Hetao Irrigation District,Inner Mongolia Autonomous Region,China.This research delves into the effects of these irrigation methods on carbon dioxide(CO_(2))exchange and crop growth in this region.The experimental site was divided into drip and flood irrigation zones.The irrigation schedules of this study aligned with the local commonly used irrigation schedule.We employed a developed chamber system to measure the diurnal CO_(2)exchange of maize plants during various growth stages under both drip and flood irrigation methods.From May to September in 2020 and 2021,two sets of repeated experiments were conducted.In each experiment,a total of nine measurements of CO_(2)exchange were performed to obtain carbon exchange data at different growth stages of maize crop.During each CO_(2)exchange measurement event,CO_(2)flux data were collected every two hours over a day-long period to capture the diurnal variations in CO_(2)exchange.During each CO_(2)exchange measurement event,the biological parameters(aboveground biomass and crop growth rate)of maize and environmental parameters(including air humidity,air temperature,precipitation,soil water content,and photosynthetically active radiation)were measured.The results indicated a V-shaped trend in net ecosystem CO_(2)exchange in daytime,reducing slowly at night,while the net assimilation rate(net primary productivity)exhibited a contrasting trend.Notably,compared with flood irrigation,drip irrigation demonstrated significantly higher average daily soil CO_(2)emission and greater average daily CO_(2)absorption by maize plants.Consequently,within the maize ecosystem,drip irrigation appeared more conducive to absorbing atmospheric CO_(2).Furthermore,drip irrigation demonstrated a faster crop growth rate and increased aboveground biomass compared with flood irrigation.A strong linear relationship existed between leaf area index and light utilization efficiency,irrespective of the irrigation method.Notably,drip irrigation displayed superior light use efficiency compared with flood irrigation.The final yield results corroborated these findings,indicating that drip irrigation yielded higher harvest index and overall yield than flood irrigation.The results of this study provide a basis for the selection of optimal irrigation methods commonly used in the Hetao Irrigation District.This research also serves as a reference for future irrigation studies that consider measurements of both carbon emissions and yield simultaneously.

Response of maize growth and soil biological characteristics to planting density under fertigation in a semi-arid region

Increasing the planting density can exacerbate crop competition for water,nutrients and space which results in a decline in the crop yields.However,the effect of increasing planting density on crop growth and soil biological characteristics in barren sandy land in the semi-arid regions are still unclear.In this study,we investigated the effects of six planting densities(5.4×10^(4),6.45×10^(4),7.95×10^(4),9.5×10^(4),9.75×10^(4) and 10.5×10^(4) plants/hm^(2))on maize growth,photosynthesis characteristics,yield and soil biological characteristics in barren sandy soil in the semi-arid region of Ningxia,China.The results indicated that the stem diameter and spike length decreased linearly with increasing planting density.The plant height,spike weight,grain weight and 100-grain weight decreased with increasing plating density.Moreover,the root length increased with increasing planting density.The diameter,volume and activity increased and then decreased with increasing planting density.There was no significant difference(p>0.05)in the effect of planting density on transpiration rate intercellular CO_(2) concentration.As well,the soil microbial biomass carbon and microbial biomass nitrogen decreased with increasing planting density.The soil catalase activities increased and then decreased with increasing planting density.The alkaline phosphatase activity,the amounts of soil bacteria and actinomycetes increased with increasing planting density.Generally,a moderately increasing planting density can improve maize yield when water and nutrients are sufficient.The optimal planting density was 8.29×10^(4) plants/hm^(2) and the highest yield was 15.84 t/hm^(2) in barren sandy soil in semi-arid region of Ningxia,China.This study provides a theoretical basis for high yield and high efficiency of maize.

Assessing Maize Drought Hazard for Agricultural Areas Based on the Fuzzy Gamma Model

Drought is one of the severe meteorological disasters and causes of serious losses for agricultural productions, and early assessment of drought hazard degree is critical in management of maize farming. This study proposes a novel method for assessment of maize drought hazard in different growth stages. First, the study divided the maize growth period into four critical growth stages, including seeding, elongation, tasseling, and filling. Second, maize drought causal factors were selected and the fuzzy membership function was established. Finally, the study built a fuzzy gamma model to assess maize drought hazards, and the gamma 0.93 was finally established using Monte Carlo Analysis. Performing fuzzy gamma operation with 0.93 for gamma and classifying the area yielded a map of maize drought hazards with four zones of light, moderate, severe, and extreme droughts. Using actual field collected data, seven selected samples for drought hazard degree were examined, the model output proved to be a valid tool in the assessment maize drought hazard. This model will be very useful in analyzing the spatial change of maize drought hazard and influence on yield, which is significant for drought management in major agricultural areas.

Effects of Nitrogen Application and Weed Interference on Performance of Some Tropical Maize Genotypes in Nigeria

Low soil nitrogen （N） and weed infestations are some of the major constraints to maize production in Nigeria. A split-split plot experiment in a randomized complete block design with three replicates was established at two sites with different agroecological zones, Ikenne （Typic Paleudalf） and Shika （Typic Tropaquept）, in Nigeria in 2002 and 2003 rainy seasons to investigate the responses of four maize genotypes （Oba super II, Low N pool C2, TZB-SR, and ACR 8328 BN C7） to N fertilizer applied at four rates, 0, 30, 60, and 90 kg N ha^-1, and three weed pressure treatments, no weed pressure （weekly weeding）, low weed pressure （inter-row weekly weeding）, and high weed pressure （no weeding throughout the growing season）. Growth and yield parameters of maize and weeds were taken at flowering and harvest. The results indicated that there was a significant reduction in maize leaf area, leaf area index, and photosynthetically active radiation due to weed interference at both sites. The application of nitrogen at 90 kg N ha^-1 significantly increased maize leaf area. Reductions in maize growth and yield at flowering and harvest were significant due to weed interference at both Ikenne and Shika, thus showing that the reductions in maize growth and yield due to weed interference were not ecological zone specific even though weed species and their seed banks may differ. Ameliorative management options could thus be the same in the two agroecological zones. Application of 90 kg N ha^-1 led to a significant increase in maize grain yield at Shika while there was no fertilizer effect at Ikenne on grain yield. There was no significant difference between 60 and 90 kg N ha^-1, suggesting that 60 kg N ha^-1 could be a possible replacement for the higher fertilizer rate at least for the identified maize genotypes. Low weed pressure treatment led to 26% and 35% reductions in maize grain yield at Ikenne and Shika, respectively, while 22% and 51% reductions, respectively, were observed due to high weed pressure. Generally, maize grain yield was higher at Ikenne than Shika. The maize genotypes Low N pool C2 and ACR 8328 PIN C7 performed better than the other genotypes at Ikenne while the maize genotype Oba super II had the best performance at harvest at Shika. Application of nitrogen increased weed biomass at flowering at Ikenne. The maize grain yield was highest in the N-efficient genotypes, Oba super II and Low N pool C2; the susceptible genotype TZB-SR had the least yield at Shika. There existed a negative and significant correlation between maize grain yield and weed biomass at both sites.

Extreme Climatic Characteristics and Their Effects on Maize Yield in Hei-longjiang Province from 1961 to 2020

This paper analyzed the extreme climatic characteristics of maize in Heilongjiang Province during different growth periods using the climate data and maize yield data from 1961 to 2020,and applied the principal component analysis to analyze the extent of different extreme climatic events affecting maize yield.The results showed that the extreme cold events showed a decreasing trend,and the extreme warm events showed an increasing trend,and the trend of extreme precipitation change was not obvious.Maize yield was negatively correlated with TN10p(cold nights),TX10p(warm days)and T8(days below the lower temperature limit),and positively correlated with TN90p(warm nights).T34(days above the upper temperature limit)and TX90p(warm days)during the tasseling-milking period were negatively correlated with the maize yield,and this part was concentrated in the southern part of Heilongjiang Province.The maize yield was positively correlated with the extreme precipitation during the seedling period and negatively correlated with the extreme precipitation during the filling-maturity period of maize,but the correlations were not significant.The effects of extreme weather events on maize yield were higher during the seedling and the filling-maturity periods than those during the jointing-tasseling and the tasseling-milking periods.The effects of extreme precipitation on the maize yield were less than those of the extreme temperature during different growth periods in all regions,but the effects of the extreme precipitation on maize yield were significantly higher in the Songnen Plain than those in other regions.There were regional differences in the impact of climate extremes on maize during different growth periods.The area with the greater impact of climate extremes during the seedling period was the Songnen Plain,the areas with the greater impact of climate extremes during the jointing-tasseling period were the northern part of the Sanjiang Plain,and the areas with the greater impact of climate extremes during the filling-maturity period were the Lesser Khingan Mountains and the semi-mountainous areas of Mudanjiang.

Role of alternate and fixed partial root-zone drying on water use efficiency and growth of maize(Zea mays L.)in gypsiferous soils

Alternate partial root-zone drying(APRD)is a water-saving method but can regulate crop physiological responses.A pot experiment has been conducted to study the efficiency of partial and fixed root-zone drying on the growth and production of maize(Zea mays L)in addition to the water use efficiency in soils with different gypsum content.The experimental treatments include three irrigation treatments,i.e.Conventional Irrigation(CI),Alternate Partial Root-zone Drying(APRD)and Fixed Partial Root-zone Drying(FPRD),and three soils with different gypsum content"(60.0[G1],153.7[G2],and 314.2[G3]g kg^(-1))".The vegetative growth,root dry mass and physiological indices(leaf relative water content,carotenoid concentration,proline)have been studied during three stages of maize plant growth(jointing,tasselling,and maturing).The Results showed that compared to CI,APRD and FPRD increased water use efficiency by 38.93 and 14.94%based on dry seed yield.In addition,compared to CI,APRD increased maize seed yield by 4.62-20.71%,while FPRD decreased yield by 19.24-5.28%for the gypsiferous soils G2 and G3,respectively.APRD has a slight effect on leaf water potential,leaf relative water content,carotenoid and proline activities from jointing to maturing stages at the three gypsiferous soils.Results suggest that APRD could make maize plants use water even more productively with better adaptation to water shortages in the gypsiferous soils.