Increased Maize Yield Research Articles

Larvicidal and feeding deterrent properties of extracts from Dieffenbachia maculata (Dumb cane) against Spodoptera frugiperda in maize (Zea mays)

This study examined the larvicidal and feeding deterrent properties of extracts from Dieffenbachia maculata against Spodoptera frugiperda (Fall army worm) in growing maize. A 9 m x 7 m space in the green house was divided into forty-two plots of 1 m by 0.75 m with 0.5 m discard between rows. This is to allow for a 2 x 3 x 4 factorial experiment replicated three times. Maize seeds were sown at two seeds per hole at a spacing of 90 cm by 60cm in each plot. Each plot was barricaded with wire mesh to prevent the migration of larvae from plot to plot. The irrigation system in the greenhouse supplied equal volume of water at the base of the maize seedlings every morning. Infested maize plants were treated with different Dumb cane plant extracts at the concentration of 25ml/l and30ml/l along with positive and negative controls. (The positive control was treated with Cypermethrine at 3l/ha) to compare the effect of concentrations on the fall army worm activity. In this experiment, the numbers of leaves affected was assessed every week and recorded. Leave perforation index was calculated. Dead armyworms were observed by prodding the larvae for movement and were recorded. Plant vigour was obtained by measuring plant height and the number of leaves formed. Effect of the worm on yield was determined by comparing total yield from sampled maize plants and this was compared to expected yield from the variety of maize used for the research. The positive control group exhibited a significantly lower level of infestation after treatment with a corresponding yield increase, (16.06% and 80.14%) respectively when compared to the treated groups. Similarly, leave extract using acetone at 30ml record significantly better results with 17.73% level of infestation after treatment application and 66.44% yield increase. This was closely followed by leaf extract using methanol at 30ml with significantly lower level of infestation and increased yield respectively. (21.35% and 60.42%). Conversely, the lowest value was recorded for the negative control. Among the extract treatments, the leaf extract using acetone at 30ml showed the highest efficacy in reducing infestation levels and demonstrated the most significant increase in maize yield. In this study, it was observed that application of the 30ml leaf extract of Dumb cane using acetone was effective and significantly increased army worm larval mortality, reduced leaf damage, and increased maize grain yield compared to the untreated control. The results indicated that the extracts from dumb cane leaves and stems exhibited promising capacity in the control of Fall army worm in maize. Further research is warranted to optimize the application protocols and evaluate any residual effects of the extracts on maize grain and ecosystem dynamics

Irrigation expansion shows potential for increased maize yield and reduced nitrogen leaching in the Midwest US

CONTEXTYield gaps in Midwest US rainfed maize (Zea mays L.) are likely to continue to increase as the frequency of extreme weather events associated with future climate change increase (i.e., high temperatures, precipitation variability). One solution to closing this gap is the expansion of irrigation in regions that currently do not utilize this practice. While irrigation expansion has the potential to increase maize yields and crop productivity, there is also the potential to see improvement in nitrogen loss. However, it remains unclear at what point irrigation should be triggered (i.e., plant available water content (AWC) thresholds) to obtain a balance between crop productivity and environmental improvements. OBJECTIVEThe objective of this study is to assess the effects of irrigation management on maize yield, nitrogen leaching, and water use efficiency under the expansion of irrigation across the entire Midwest US and to determine the optimal plant AWC threshold to trigger irrigation for achieving a substantial increase in maize yield and reduction in nitrogen leaching while using the minimal amount of required irrigation. METHODSWe use an agroecosystem model, Agro-IBIS, to simulate both rainfed and irrigated maize production and nitrogen leaching under likely future climate conditions (i.e., wet-warm, dry-warm). To determine the optimal plant AWC threshold for irrigation, irrigation scenarios were conducted for a range of plant AWC thresholds (0.2 to 0.8) across the entire Midwest US. RESULTS AND CONCLUSIONSOur results show that Midwest US regions that do not currently utilize irrigation could experience an 11–37% increase in maize yield and a 12–32% decrease in nitrogen leaching when irrigation (39.0 to 96.8 mm yr−1) is triggered at the lower end of the plant AWC threshold (e.g., 0.3). Maize grown under dry-warm and wet-warm climate conditions will likely experience increased yields and reduced nitrogen loss with minimal irrigation. While these findings suggest that the expansion of irrigation could help close yield gaps while improving other ecosystem services, future work should focus on simulating these conditions under a wider range of precipitation extremes and fertilizer management to better understand the potential interactions under a changing climate. SIGNIFICANCEThis study outlines the optimal plant AWC threshold for irrigation to maximize maize yields in the Midwest while minimizing nitrogen loss and can provide valuable insights for making informed decisions about landscape management under future conditions.

RELATIONSHIP BETWEEN RAINFALL VARIABILITY AND MAIZE YIELD IN APA LOCAL GOVERNMENT AREA OF BENUE STATE, NIGERIA

This study investigated the relationship between rainfall variability and maize yield in Apa Local Government Area of Benue State. The specific objectives were to analyse the trend in rainfall distribution and its impact on maize yield and to provide recommendations to improve maize productivity in the study area. Rainfall data was sourced from the archives of the Nigerian Meteorological station, Oshodi, Lagos; the maize yield data was collected from the archives of Benue State Agricultural and Rural Development Agency (BNARDA). The rainfall and maize yield data for 33 years (1988-2021) were used to characterise the maize yield response to rainfall pattern (increase or decrease). Trend-line equation was used to show the trend of rainfall, while Pearson's Correlation Coefficient (r) showed the degree of relationship between rainfall and maize yield. The results of the trend-line regressions showed an increase in total annual rainfall (y = 7.1873x + 1106.4) and an increase in maize yield (y = 0.0319x + 2.3239). The correlational trend chart showed a positive relationship between total annual rainfall and maize yield (r = 0.19), indicating that rainfall positively influenced yield. The study recommended that early warning weather information and climate-resilient varieties are needed to improve maize productivity. Extension services should also be provided to enhance farmers' knowledge on rainfall variability and its effects on maize yield.

Innovative fertilizer management system maintains higher maize productivity with lower environmental costs in the Loess Plateau region of China

ContextInnovative fertilizer management is the most effective strategy for increasing crop yields and reducing environmental pollution. ObjectivesDeep fertilization reduces NH3 emissions and increases crop yield, but its effects on N2O emissions are still unclear. Nitrification or urease inhibitors trigger cross-contamination of N2O and NH3. Little is known about whether innovative fertilizer management strategies can reduce nitrogen emissions while maintaining higher yields. MethodsWe conducted field experiments using maize in the semi-humid and drought-prone areas of the Loess Plateau in China from 2019 to 2021. To further verify the research results, experiments were conducted in semi-arid and drought-prone areas in 2022 and 2023 using surface fertilization (SF), surface fertilization with nitrification (SNI) or urease inhibitor (SUI), deep fertilization (DF), and deep fertilization with urease and nitrification inhibitor (DUN) as experimental treatments. ResultsThe trends were similar at the three experimental locations over five years, where the ability of DF to reduce emissions was equivalent to those of SNI for N2O and SUI for NH3. However, the increase in the crop productivity was significantly higher under DF than SUI and SNI. Compared with SF, DF significantly reduced the N2O and NH3 emissions by 39.85 % and 46.08 %, respectively, and significantly the increased maize yield, N uptake, and nitrogen use efficiency (NUE) by 16.86 %, 15.83 %, and 32.79 %. The innovative fertilizer management strategies combined the advantages of inhibitors and deep fertilization, and they obtained the highest maize yield and NUE, as well as the lowest N2O and NH3 emissions and gaseous nitrogen loss intensity (GNLI) among all treatments. Compared with SF, DUN reduced the urease, nitrate reductase, nitrite reductase, and hydroxylamine reductase activities by 22.03 %, 58.81 %, 52.72 %, and 50.27 %, respectively, the soil NO3–-N and NH4+-N contents by 82.94 % and 53.71 %, and N2O and NH3 emissions by 80.79 %, and 79.33 %. DUN increased the maize yield and NUE by 23.30 % and 46.91 %, respectively, and decreased the GNLI by 84.69 %. ConclusionsDUN reduced the concentration of substrates for producing gaseous nitrogen by regulating the activities of soil nitrogen circulating enzymes to significantly reduce the nitrogen loss, and it achieved the highest maize yield (11,818.10 kg ha–1) and NUE (46.62 %) with the lowest GNLI (0.71 g N kg–1 grain). Innovative fertilizer management strategies can help to balance economic and environmental benefits in the Loess Plateau region of China. ImplicationsOur findings provide a reference for obtaining higher maize productivity with low environmental pollution in the Loess Plateau region of China.

Reducing fertilization with high planting density increases maize yield stability and nitrogen use efficiency in semi-arid areas

High-density planting is a vital cultivation measure to improve crop yield. In the semi-arid region, insufficient precipitation and high variability are the primary factors that restrict agricultural development. Matching planting density and fertilizer application with precipitation is a promising technical strategy to ensure yield stability and enhance nitrogen (N) use efficiency (NUE). To achieve this objective, we conducted a continuous field experiment in the Loess Plateau region of Northwest China between 2015 and 2020. Under conventional (CF) and reduced fertilization (RF, 20 % CF) conditions, we investigated the response characteristics of dry matter accumulation, yield, yield components, NUE, N surplus, and net income of maize as the density increased from 5.25 (D1) to 6.75 (D2), 8.25 (D3), and 9.75 (D4) × 104 plants ha−1. The results indicated that reduced fertilizer application led to a decrease in grain yield by 6.2–8.7 %, whereas increasing the density by at least 1.50 × 104 plants ha−1 (D2) could compensate for the yield reduction caused by reduced fertilization (N 55 + P2O5 27 kg ha−1) in normal and wet years. The compensatory effect initially increased and then decreased as the density increased, with the highest yield observed at planting density D3. By increasing the rapid growth rate of maize (6.3–17.1 %) and extending the rapid growth duration (0.9–2.5 days) through high planting density, reduced fertilization combined with high-density planting (RF·D3) significantly increased the cumulative yield, yield stability, net income, and NUE was by 9.4 %, 18.9 %, 10.6 %, and 37.0 %, respectively, over six years, compared with CF·D1 treatment. Additionally, the N surplus was reduced by 44.6 %. In conclusion, using reduced fertilization with high planting density measures can achieve yield stability and sustainable maize production in semi-arid areas.

Seven-year long-term inoculation with Funneliformis mosseae increases maize yield and soil carbon storage evidenced by in situ 13C-labeling in a dryland

Arbuscular mycorrhizal fungi (AMF) establish symbiotic relationships with roots of most plants, contributing to plant water uptake and soil carbon (C) sequestration. However, the interactive contribution and of long-term field AMF inoculation and water conservation on maize yield and soil organic carbon (SOC) sequestration in drylands remain largely unknown. After 7-year long-term field inoculation with AMF Funneliformis mosseae, AMF suppression by fungicide benomyl, and no-AMF/no-benomyl control, and two water conservation practices of half-film and full-film mulching (∼50 % and ∼100 crop planted area covered with plastic film), this study thus applied in situ 13CO2-C labeling and high-throughput sequencing to quantify newly photosynthetically assimilated C into different soil C pools including soil aggregates and respiration, and their effects on maize growth and productivity. Results showed that 7-year long-term AMF inoculation significantly increased the relative abundance of F. mosseae in rhizosphere soil and root AMF colonization, indicating that F. mosseae successfully dominated in AMF communities. Compared to no-AMF/no-benomyl control, AMF colonization significantly increased shoot biomass and maize yield by 17.9 % and 20.3 % while mitigated the less water conservation effects of half-film mulching on maize performance. The SOC content under field AMF inoculation SOC was increased from 7.9 to 8.4 g kg−1 and also the mean weight diameter of aggregates (1.21 to 1.35), e.g. aggregate stability. After 1 and/or 40 days 13C labeling, the enhanced 13C translocations into macro-aggregates with decreased 13C emissions from microbial decomposition under field AMF inoculation had contributed to SOC conservation in bulk soil. These results suggest that AMF inoculation in dryland crops is promising to increase crop yield while promoting more atmospheric CO2 fixation in soil aggregates. A long-term field AMF inoculation will enhance our understanding of applying beneficial mycorrhizal fungi to enhance soil C sequestration and also crop yield via plant-fixed atmospheric CO2 in semi-arid and arid farmlands.

Effects of Maize/Peanut Intercropping on Yield and Nitrogen Uptake and Utilization under Different Nitrogen Application Rates

The effects of maize/peanut intercropping on crop yields, peanut nodulation, biological nitrogen (N) fixation in peanuts, crop N uptake, and N use efficiency under different N application rates were studied. A long-term maize/peanut intercropping micro-plot experiment was started in 2015. The experiment included the following three planting patterns: maize sole crop (SM), peanut sole crop (SP), and maize and peanut intercropping (intercropping maize: IM; intercropping peanut: IP). Additionally, three N application rates were tested as follows: 0 kg·ha−1 (N0), 150 kg·ha−1 (N150), and 300 kg·ha−1 (N300). The results indicated that N fertilization significantly increased maize yield. Intercropping increased maize yield while decreasing peanut yield across different N application rates. Both N fertilization and intercropping significantly increased the maize harvest index (HI), whereas intercropping decreased the peanut HI under N300. The number and fresh weight of peanut nodules decreased with the increasing N application rate with reductions ranging from 31.15% to 45.23% and 39.60% to 46.67%, respectively. Intercropping increased the number of peanut nodules by an average of 62.56% under the N0 treatment. Intercropping significantly improved the N absorption capacity of the whole intercropping system, and the contribution of maize was higher than that of peanuts. Maize demonstrated a stronger competitive ability for N uptake compared with peanuts in the intercropping system. Intercropping significantly increased the N use efficiency for both maize and peanuts. However, the N use efficiency of maize increased with N application rates, while that of peanut decreased. Compared with sole crops, intercropping increased the partial factor productivity of maize by 55.2% but decreased that of peanuts by 56.3%. In conclusion, at an N application rate of 150 kg·ha−1, maize/peanut intercropping increased overall crop yield and improved the N absorption and use capacity of maize

Effects of Climate Change Adaptation Strategies on Maize Productivity among Smallholder Farmers in Dodoma, Tanzania

This study sought to establish the impact of climate change adaptation strategies on maize productivity among smallholder farmers in Dodoma, Tanzania. Employing a cross-sectional research design, data was collected from 274 respondents who were randomly selected. A structured questionnaire was utilized for data collection, and the Propensity Score Matching (PSM) technique was employed to estimate the effects of climate adaptation strategies on maize productivity. The findings indicate that smallholder farmers who adopted climate change adaptation tactics achieved higher maize yields compared to non-adopters. Additionally, results from multiple linear regression demonstrate that increased maize yields are associated with the adoption of drought-resistant maize varieties, intercropping, minimal tillage, adjusted planting dates, fertilizers, irrigation and short-duration maize varieties. Notably, crop rotation showed no significant effect on maize productivity. Policy recommendations include government investment in promoting the adoption of climate change adaptation strategies among smallholder farmers to mitigate losses and improve the farmers’ well-being. Furthermore, investments in modern irrigation schemes and the use of drought-resilient seeds are deemed crucial for enhancing agricultural resilience in the face of climate change.

Farmers’ preferences for adopting agroforestry in the Eastern Province of Rwanda: A choice experiment

Agroforestry is recognized as an effective land restoration strategy in Rwanda. To effectively implement agroforestry practices, it is crucial to examine and address the preferences of farmers. However, there is limited knowledge concerning farmers’ preferences for different agroforestry characteristics and their level of willingness to engage in such systems. This paper examines farmers’ preferences for adopting agroforestry in the Eastern Province of Rwanda using a discrete choice experiment (DCE) conducted among 248 households. The analysis conducted at plot level included a total of eight attributes: number of fruit trees, number of non-fruit trees, root system and canopy, change in maize yield resulting from tree planting, extension assistance, additional labor, distance to the tree nursery, and the cost of tree seedlings. Results indicate that farmers are generally willing to adopt agroforestry practices. They prefer agroforestry systems that incorporate non-fruit and particularly fruit trees, trees with smaller canopies, agroforestry systems with potential to increase maize yields, and regular extension assistance. However, farmers dislike increases in the cost of tree seedlings. Furthermore, findings reveal two distinct latent classes of plots, encompassing 34.5 % (Class 1) and 65.5 % (Class 2) of the plots. Farmers in Class 1 possess plots that are farther away from their homesteads and are indifferent towards the number of trees to be planted but prefer trees that increase maize yields. Farmers in Class 2 exhibit a strong inclination towards planting a greater number of trees that increase maize yields and have a small canopy. The proximity to tree nurseries and the availability of low-cost tree seedlings contribute to the likelihood of tree planting in this class. This study recommends aligning agroforestry-related policies and interventions with the preferences and needs of the farmers, taking into account plot characteristics.

Exogenous application of 5-NGS increased osmotic stress resistance by improving leaf photosynthetic physiology and antioxidant capacity in maize.

Drought is a critical limiting factor affecting the growth and development of spring maize (Zea mays L.) seedlings in northeastern China. Sodium 5-nitroguaiacol (5-NGS) has been found to enhance plant cell metabolism and promote seedling growth, which may increase drought tolerance. In the present study, we investigated the response of maize seedlings to foliar application of a 5-NGS solution under osmotic stress induced by polyethylene glycol (PEG-6000). Four treatment groups were established: foliar application of distilled water (CK), foliar application of 5-NGS (NS), osmotic stress + foliar application of distilled water (D), and osmotic stress + foliar application of 5-NGS (DN). Plant characteristics including growth and photosynthetic and antioxidant capacities under the four treatments were evaluated. The results showed that under osmotic stress, the growth of maize seedlings was inhibited, and both the photosynthetic and antioxidant capacities were weakened. Additionally, there were significant increases in the proline and soluble sugar contents and a decrease in seedling relative water content (RWC). However, applying 5-NGS alleviated the impact of osmotic stress on maize seedling growth parameters, particularly the belowground biomass, with a dry mass change of less than 5% and increased relative water content (RWC). Moreover, treatment with 5-NGS mitigated the inhibition of photosynthesis caused by osmotic stress by restoring the net photosynthetic rate (Pn) through an increase in chlorophyll content, photosynthetic electron transport, and intercellular CO2 concentration (Ci). Furthermore, the activity of antioxidant enzymes in the aboveground parts recovered, resulting in an approximately 25% decrease in both malondialdehyde (MDA) and H2O2. Remarkably, the activity of enzymes in the underground parts exhibited more significant changes, with the contents of MDA and H2O2 decreasing by more than 50%. Finally, 5-NGS stimulated the dual roles of soluble sugars as osmoprotectants and energy sources for metabolism under osmotic stress, and the proline content increased by more than 30%. We found that 5-NGS played a role in the accumulation of photosynthates and the effective distribution of resources in maize seedlings. Based on these results, we determined that foliar application of 5-NGS may improve osmotic stress tolerance in maize seedlings. This study serves as a valuable reference for increasing maize yield under drought conditions.

Effects of Film Mulching on Soil Microbial Diversity and Community Structure in the Maize Root Zone under Drip Irrigation in Northwest China

Mulching is a widely used agricultural water conservation measure in the semiarid regions of Northwest China. In order to explore the response process of different film mulching methods to soil microorganisms, we characterized the effect of different film mulching methods on soil microbial diversity and community structure characteristics in the root zone of drip-irrigated maize during the heading and maturity stages using high-throughput sequencing of 16SrDNA and ITS amplicons combined with bioinformatics analysis. Full mulching (FM) was contrasted to controls of no mulching (NM) and half-mulching (HM), yielding an order of microbial diversity, abundance, and evenness scores of HM > FM > NM. The HM and FM treatments reduced the relative abundance of Proteobacteria and Actinobacteria (the most abundant bacteria) in the bacterial community structure but increased that of Acidobacteria and Chloroflexi. In the fungal community structure, HM decreased the abundance of Sordariomycetes but increased that of Eurotiomycetes (the most abundant fungi). The abundance and community structure of bacteria were significantly correlated with soil temperature and those of fungi with pH. HM improved network complexity and competitive relationships among bacteria, while FM increased the relationship between fungal groups and the symbiosis of fungal communities. HM significantly increased maize yield (20.37% and 6.01% above NM and FM, respectively). In summary, full mulching was more favorable than no mulching for soil microbial diversity and community structure composition, but soil microbial diversity and yield responded better to half-mulching. These results provide a background for improving the yield of drip-irrigated maize and protecting the microbial ecosystems of farmland soils.

Impact of new maize variety adoption on yield and fertilizer input in China: Implications for sustainable food and agriculture

CONTEXTCrop variety adoption is considered as one of the main strategies for farmers to enhance productivity under stress brought by the climate change, with less environmental impacts. It holds an upstream position in the whole life cycle of agricultural clean production, compared to the field management and agricultural non-point source pollution treatment. OBJECTIVEThis paper aims to (i) assess the impact of new maize variety adoption on maize yield and fertilizer input; (ii) analyze the main determinants of farmers' new maize variety choice in the context of climate change, and (iii) identify the heterogeneity of small-scale and large-scale farmers in maize variety choice and its impacts. METHODSBased on plot-level data collected from three major grain producing provinces in China, we employ a treatment effects model to correct the potential bias resulting from the farmers' self-selection and estimate the direct impacts of farmers' new maize variety adoption and the main determinants of such adoption. RESULTS AND CONCLUSIONSThe empirical results indicate that the adoption of new maize varieties significantly increases maize yield by 9.4% but fertilizer use by 16.6 kg/mu (1 mu = 1/15 ha) as well, and this trade-off between economic impacts and environmental impacts is more pronounced among small-scale farmers. However, in the face of natural disasters, adopting new maize varieties results in a significant reduction in yield losses by 1.4% and a decrease in fertilizer input for natural disaster management by 2.45 kg/mu, as compared to the adoption of old varieties. What's more, our findings suggest that a higher frequency of pest and disease disasters significantly increases the probability of new maize variety adoption by farmers, while a higher frequency of climate disasters significantly decreases the probability. SIGNIFICANCEThe estimated impacts of new maize varieties point out the need of synergistically optimized resistance and nutrient use efficiency for crop breeding, which have important policy implications for sustainable food and agriculture. Also, the significant factor analysis contributes to the proposal of feasible ways to promote the farmers' adoption behavior.

Influence of Pteris vittata-maize intercropping on plant agronomic parameters and soil arsenic remediation

To achieve “production while remediation” in arsenic (As) -contaminated farmlands, a field experiment was conducted to investigate the effects of five Pteris vittata L. (PV) - maize intercropping modes on the growth, nutrient, and As accumulation characteristics of PV and maize. The intercropping increased the As content of PV by 2.9%–132.0% and decreased the As content in maize shoots by 15.5%–37.0%. Total As accumulation in above-ground plant parts reached 202.03–941.97 g hm−2. Intercropping also improved nitrogen and phosphorus content in maize kernels by 27.6%–124.7% and 15.9%–31.5%, respectively. Additionally, intercropping increased maize kernel 100-grain weight by 10.0%–16.6% and resulted in a 1.1%–24.1% increase in maize yield compared to sole cultivation. The intercropping transformed soil As from iron-bound to calcium-bound and aluminum-bound forms. Analysis of soil microbial diversity showed that the intercropping decreases the abundance of Chloroflexi and increases the abundance of Proteobacteria. Among the five modes, the intercropping mode with 4 rows of maize and 4 rows of PV showed the highest remediation efficiency and mechanized operation. These findings contribute to a theoretical framework and technical support for the simultaneous soil pollution remediation and productive farming practices.

Incorporating canopy radiation enhances the explanation of maize yield change and increases model accuracy under film mulching

Plastic film mulching (PM) has been extensively used to increase crop yields in dryland regions in China. However, the impact of differently colored PM on crop radiation utilization due to the optical properties of the underlying PM surfaces remains unclear. We conducted a two-year field experiment in northwest China to evaluate the dynamics of photosynthetically active radiation interception and absorption (fIPAR and fAPAR), as well as the radiation use efficiency for intercepted and absorbed radiation (RUEi and RUEa) during spring maize (Zea mays L.) growth periods. Two fertilization levels (high and low) and 3 PM treatments (transparent film, black film, and no film) were considered in this study. We also developed empirical regression functions to calculate canopy fAPAR, accounting for both canopy and underlying surface characteristics. Furthermore, we used canopy absorption radiation to drive the Soil-Plant-Atmosphere Continuum System (SPACSYS) model to simulate maize biomass and yield. We found that transparent film mulching (TM) exhibited higher fIPAR and fAPAR than black film mulching and no mulching (CK). TM had an increase of RUEi and RUEa by 10.6% and 9.7%, respectively, relative to CK, resulting in a 9.3–19.2% increase in maize yield and a 25.8–30.2% increase in the partial factor productivity of nitrogen. These increases were mainly attributed to the increased relative chlorophyll content, net photosynthesis rate, and extended grain-filling period under TM. We found that the modified radiation input increased the accuracy of the SPACSYS model in simulating maize biomass and yield. We underscore the importance of using TM in dryland areas to increase crop yields and advocate for incorporating canopy radiation data into crop models, especially in agricultural regions where plastic film mulching is used, to enhance the accuracy of yield simulations.

Appropriate Application of Organic Fertilizer Can Effectively Improve Soil Environment and Increase Maize Yield in Loess Plateau

Fertilization has a significant impact on soil nutrients and microbiological properties, which, in turn, affect crop yield. However, the specific effects of organic and inorganic fertilizers on soil fertility and microbial characteristics in maize fields, as well as the key soil factors influencing changes in crop yield, remain largely unknown. A study was conducted over two years (2021–2022) to investigate the impact of various nitrogen fertilization rates and types on maize yield and soil properties in the Loess Plateau. Field experiments with five nitrogen levels (60, 90, 120, 150, and 180 kg N ha−1) and two fertilizer types (chemical and organic) were conducted. The optimal yield was achieved with 150 kg N ha−1, significantly surpassing that of other treatments by 4.5−45.7%. Compared with the organic fertilizers, the chemical fertilizers increased soil salt and catalase levels, with soil nitrate and ammonium content being higher at the jointing stage but lower at maturity. Organic fertilization improved soil potassium, organic matter, urease and phosphatase activities, and microbial populations. Yield correlated with several soil indicators, including salt content, nitrate, available potassium, and enzyme activities. Notably, soil nitrate also correlated with actinomyces quantity. A principal component analysis showed that the organic fertilizer was more beneficial to soil health than the chemical fertilizer. Consequently, this study recommends 150 kg N ha−1 of organic fertilizer for sustainable maize farming and soil health in China’s northwest arid region, providing a theoretical framework for agricultural practices.

The effects of contour-based rainwater harvesting and integrated nutrient management on maize yields in semi-arid regions of Zimbabwe

In the smallholder farming areas located in semi-arid regions of Zimbabwe, low and unreliable rainfall distribution and poor soil fertility are the major factors limiting crop production. The negative effects of these biophysical factors have been worsened by climate change. However, the major challenges have been the lack of sustainable, low-cost water and nutrient management technologies for these semi-arid regions. The objectives of this study were to evaluate the effects of contour-based rainwater harvesting (RWH) namely tied contours (TC), infiltration pits (IP) which were compared with the standard contour (STDC), and intergrated nutrient management (INM) where cattle manure was used as basal fertiliser and Ammonium Nitrate (AN) as top dressing, on maize yields. Results showed that fields with RWH had higher yields compared to STDC. Average maize yields were 2210 and 1792 kg ha−1 for TC and IP which were 88% and 52% above STDC (1176 kg ha−1) respectively. Increasing nitrogen (N) levels resulted in a further increase in maize yields. Return on investment was negative during drier years and was significantly higher in RWH systems compared with STDC during wet seasons. Farmers need to reduce mineral fertiliser application during dry seasons since little rainwater is captured. We conclude that contour based RWH and INM can be used as sustainable low cost methods of crop production. Higher fertiliser application rates when rainfall is limiting, do not result in increased return on investiment.

Inversion Tillage Combined with Organic Fertilizer Application Increased Maize Yield via Improving Soil Pore Structure and Enzymatic Activity in Haplic Chernozem

Inversion tillage and organic fertilizer application can break the plow pan and improve soil quality. However, the effects of combining these practices on the soil microbial resource limitation and maize yield in Haplic Chernozem are unclear. In this research, a field experiment was established in 2018, and soil samples were collected in 2021 in Longjiang County in Northeast China, which is a Haplic Chernozem region. Four treatments comprising conventional tillage (T15), conventional tillage with organic fertilizer (T15+M), inversion tillage (T35), and inversion tillage with organic fertilizer (T35+M) were randomly arranged with four replications. Compared with T15 and T15+M treatments, soil bulk density significantly decreased by 11.1–16.3% in the 15–35 cm layer under T35 and T35+M treatments, accompanied by the improvement in soil pore structure (e.g., soil porosity, circularity, and Euler number). T15+M treatment significantly increased soil organic carbon and soil nutrient contents by 11.1–16.3% and 3.9–24.5% in the 0–15 cm layer compared with other treatments. However, soil organic carbon, total nitrogen, available phosphorus content, microbial biomass, and enzymatic activities reached the maximum values in the 0–35 cm layer under T35+M treatment. In addition, T35+M treatment had the highest maize yield and sustainable yield index. Extracellular enzymatic stoichiometry suggested that soil microorganisms are generally co-limited by carbon and phosphorus in Haplic Chernozem. However, T35+M treatment significantly reduced soil microbial resource limitation, which was one important factor impacting maize yield and sustainability. Random-forest and partial least-squares path modeling showed that T35+M treatment could reduce soil microbial resource limitation and increase the stability and sustainability of the maize yield by improving soil available nutrients, microbial biomass, and pore structure. Therefore, the incorporation of inversion tillage and organic fertilizer is a suitable soil management practice in view of increasing soil quality and crop yields in a Haplic Chernozem region.

Further adoption of conservation tillage can increase maize yields in the western US Corn Belt

Conservation tillage can reduce soil erosion, increase soil health, and decrease labor and fuel input costs. Despite these benefits, potential yield impacts remain an important concern for farmers considering adoption. Previous research suggests that conservation tillage is likely to have the largest yield benefits in more arid conditions, but a lack of field-level analyses across climatic, management and soil conditions limits confidence in such predictions. Satellite imagery provides the opportunity to monitor agricultural lands at sub-field resolution across large spatial scales and wide environmental gradients. Here we investigate the maize yield impacts of conservation tillage in the semi-arid western US Corn Belt, using sub-field resolution datasets on tillage practices and crop yields derived from satellite data spanning four states (Nebraska, Kansas, South Dakota, and North Dakota) between 2008 and 2020. On these datasets, we estimate heterogenous yield outcomes for several thousand maize fields across gradients in climate, soil quality and irrigation status by using a causal forests analysis, an adaptation of the random forests machine-learning algorithm for causal inference on observational data. We find that long-term adoption of conservation tillage increased rainfed maize yields by an average of 9.9% in the region. Impacts on irrigated yields were small and not statistically significant. These results, along with an analysis of variables related to greater than average yield benefits, indicate that improved water infiltration and retention are the primary reasons for conservation tillage benefits. Despite yield benefits, many fields estimated to see increased yields under long term low till have not adopted the practice. Therefore, we identify specific counties likely to benefit most from increased levels of adoption. Our results strengthen the understanding of the impacts of conservation agriculture on crop yields and help define environments and counties most likely to benefit from conservation tillage.

Polyaspartic Acid Urea Increased Maize Yield by Enhancing Leaf N Turnover Efficiency and Soil Microbial Diversity

The release rates of different nitrogen (N) fertilizers and their matching with plant demand determine crop yields. A field experiment was conducted to investigate the effect of using no fertilizer (N0), regular urea applied at rates of 180 kg ha−1 (N180) and 240 kg ha−1 (N240), controlled-release urea applied at a rate of 180 kg ha−1 (H180), and polyaspartic acid urea (PASP) on maize seed yield, soil microbial community diversity, and leaf N-converting enzymes. XianYu 688 was selected as the test maize variety. All cobs in the sample plots were collected per unit area to estimate maize yield. The enzyme-linked immunosorbent assay (ELISA) was used to determine leaf N-converting enzyme activities. Soil DNA was extracted using the Power Max Soil DNA Isolation Kit and subsequently sequenced using the Illumina HiSeq platform (PE 2500) to determine the microbial diversity and communities. The results showed that the highest seed yields were obtained under N240 and PASP180 treatments. The N-partial factor productivity of the PASP180 fertilizer was significantly higher than that of the other treatments. PASP treatment significantly increased maize seed yield due to the potential of storing more N in the ear leaves. Additionally, partial N productivity showed a significant positive correlation with the soil microbial Shannon, Chao1, and ACE indices, indicating that increased soil microbial diversity promoted N efficiency in maize. Further analysis revealed that PASP treatment increased seed yield by promoting leaf N-converting enzyme activity and soil microbial diversity. The results revealed that nitrate reductase (NR), glutamate synthase (GOGAT), and glutaminase (GLNS) enzyme activities in maize leaves were higher under the PASP treatment than under other fertilizer treatments. The PASP treatment significantly enhanced soil microbial diversity at different maize stages. Our study revealed the effects of using different N fertilizers on seed yield by examining their impact on soil microbial diversity and leaf N-converting enzyme activity. This study provides essential insights into maize production and soil fertility maintenance in the North China Plain.

Root proliferation adaptation strategy improved maize productivity in the US Great Plains: Insights from crop simulation model under future climate change

Adaptation measures are essential for reducing the impact of future climate risks on agricultural production systems. The present study focuses on implementing an adaptation strategy to mitigate the impact of future climate change on rainfed maize production in the Eastern Kansas River Basin (EKSRB), an important rainfed maize-producing region in the US Great Plains, which faces potential challenges of future climate risks due to a significant east-to-west aridity gradient. We used a calibrated CERES-Maize crop model to evaluate the impacts of baseline climate conditions (1985–2014), late-term future climate scenarios (under the SSP245 emission pathway and CMIP6 models), and a novel root proliferation adaptation strategy on regional maize yield and rainfall productivity. Changes in the plant root system by increasing the root density could lead to yield benefits, especially under drought conditions. Therefore, we modified the governing equation of soil root growth in the CERES-Maize model to reflect the genetic influence of a maize cultivar to improve root density by proliferation. Under baseline conditions, maize yield values ranged from 6522 to 12,849 kgha−1, with a regional average value of 9270 kgha−1. Projections for the late-term scenario indicate a substantial decline in maize yield (36 % to 50 %) and rainfall productivity (25 % to 42 %). Introducing a hypothetical maize cultivar by employing root proliferation as an adaptation strategy resulted in a 27 % increase in regional maize yield, and a 28 % increase in rainfall productivity compared to the reference cultivar without adaptation. We observed an indication of spatial dependency of maize yield and rainfall productivity on the regional precipitation gradient, with counties towards the east having an implicit advantage over those in the west. These findings offer valuable insights for the US Great Plains maize growers and breeders, guiding strategic decisions to adapt rainfed maize production to the region's impending challenges posed by climate change.