Maize Production Systems Research Articles

Increased Maize Yield in Response to Applied Phosphorus and Nitrogen in the Greenbelt Zone, in South Sudan

Aims: The study focused on assessing the impact of applying phosphorus and nitrogen fertilizers on maize yield in the Greenbelt zone of South Sudan, where nutrient deficiencies often limit crop growth.
 Study Design: Field experiments involved a 4 x 4 x 4 factorial experiments in a randomized complete block design. The field experiment was conducted in Sakure and Nginda Payams in Nzara and Yambio Counties respectively, between August 2020 and January 2022.
 Methodology: The treatments involved Triple Super Phosphate (TSP, 0-46-0) applied at 20, 40 and 60 kg P ha -1 without N, Urea (46% N) applied at 40, 80 and 120 kg N ha-1 without P, combinations of each level of P with varying levels of N and an absolute control (P0N0). Maize variety was an open pollinated called NARD 1. Plot size was 16 m2, all maize plant above ground was harvested in a net plot (8.5 m2) after 120 days.
 Results: The average maize yield in response to applied fertilizer P and N in the three sites was 4.7 t ha-1 an increase of about 62 % over the control (2.9 t ha-1), and was statistically significantly at P = .05
 Conclusion: 20 kg P ha-1 and 120 kg N ha-1 rates were profitable and therefore were recommended as optimum application rates that can contribute to food security and economic progress in the area. However, more research is recommended to establish long-term fertilizer effects on maize performance, optimal application rates, and environmental considerations. The study stressed the need for diversified fertilizer research across seasons and emphasized community awareness about fertilizer benefits for sustainable maize production and farming system research.

Effect of Planting Density on the Nutritional Quality of Grain in Representative High-Yielding Maize Varieties from Different Eras

Maize is essential in ensuring food security in China as a primary food and feed crop. One of the main ways to increase yield in maize production systems is to increase planting density as appropriate. Clarifying the relationship between planting density and grain nutritional quality can provide theoretical guidance for high-yielding high-quality maize cultivation and management practices. To this end, five representative high-yielding maize varieties from the 1970s to the 2010s in China were used as experimental material, and two planting densities of 45,000 plants hm−2 and 105,000 plants hm−2 were set to analyze the changing patterns of yield traits and grain nutrient quality of maize varieties in different eras, as well as their responses to densification conditions. The results showed that, under low-density conditions, the grain nutrient quality components of the 2010s’ variety (DH618) were all different 75 days after anthesis compared with the 1970s’–2000s’ varieties and yields also significantly increased by 11.15% to 19.18% (p < 0.05). The increase in planting density led to a rise in total grain starch and soluble sugar content 75 days post-anthesis in all varieties from the 1970s to the 2010s, with increases of 0.65–1.65% and 39.44–69.01%, and a decrease in crude grain protein and crude fat content, with reductions of 4.15–8.50% and 3.00–11.18%. The increase in total grain starch content 75 days post-anthesis was mainly due to the rise in grain starch accumulation between 23 and 47 days post-anthesis in the 1970s’–2010s’ varieties, with an increase of 7.72–9.19% in all varieties. The higher accumulation of crude fat and soluble sugar in the 0–23 days post-anthesis period also contributed to the increase in total starch accumulation in the 23–47 days post-anthesis period. Ultimately, densification conditions also contributed to a significant increase in yield across all eras of the varieties based on changes in grain nutritional quality, with a more significant increase in yield due to densification and a smaller decrease in grain crude fat content due to densification 75 days after anthesis in the 2010s’ variety (DH618). Therefore, in cultivation and production processes that do not have specific requirements for the nutritional quality components of maize grain, we suggest that the use of a representative high-yielding maize variety (DH618) from the 2010s, together with appropriate planting at close planting distances, can significantly increase maize yields based on an increase in the total starch content of the grain at physiological maturity.

Corn production and processing into ethanol in Turkey: An analysis of the performance of irrigation systems at different altitudes on energy use and production costs

This research aims to assess the energy input and output involved in corn production in the Elazig province of Turkey in different agricultural systems. This study is interested in energy resource allocation to analyze maize production systems since the value of production inputs and outputs is affected by economic crises as well as the country's politico-economic status. The amounts of energy used for production are still very challenging to change. The typical energy usage of the farms examined in this study is 3359,82 MJda−1, 3715,74 MJda−1, 5366,13 MJda−1 and 6456,24 MJda−1 according to the distance between the water sources and the farms. Of the total mean of energy, 31.06% is direct, 12, 26% is indirect, 14,38% in renewable energy and 42,30% in non-renewable energy. A kilogram of typical maize is thought to require 3,93 MJ of energy in total to produce. Energy used for irrigation makes up most of the input (37.20%), followed by sowing (22.57%) and fertilizer (16.65%). As a result of the benefit-cost ratio analysis is 0.29, the cost of corn production per decare is found to be $112.05/da in the area, with variable costs accounting for 83.17% of the total. The analysis of data reveals that the transformation of 100 kg of corn generates an energy expenditure of 2219.58 MJ and more than 50% of energy expenditure comes from the use of machines.

Spatial variability of soil secondary and micronutrients under smallholder maize production system in sub-humid condition of Zimbabwe

Achieving household and national food security is the core focus for policy makers in sub-Saharan Africa (SSA). However, land degradation and dearth of effective soil nutrient management strategies for spatially variable soils is significantly contributing to food insecurity in SSA. The aim of this study was to establish the spatial variability of soil secondary and micronutrients (SMN) under smallholder maize production system in sub-humid condition of Zimbabwe. Geo-referenced samples collected in all maize fields in seven of the eleven villages in ward 10 of Hurungwe district using purposive sampling were analyzed for Ca, Mg, Fe, Mn, Cu and Zn using standard methods. Pearson's correlation analysis was conducted to reveal the relationships among the nutrient status. The linear mixed model (LMM) was used to analyse spatial variation of the data with evidence for spatial dependence in the random component of the model assessed by calculating Akaike's information criterion (AIC). The results indicate that only Ca was significantly (p < 0.05) influenced by field type with larger concentrations in home fields compared to outfields. Soil texture had a significant (p < 0.05) effect on Ca, Mg and Zn with the largest values for Ca and Mg found in the sandy clay loams (with the largest clay content) compared to sand, loamy sand and sandy loam. Loamy sand had the largest Zn concentration with sandy clay loams having the least. There was evidence for spatial dependence in Ca and Mg with field type, latitude and longitude as fixed effects; hence these nutrients were mapped in the GIS environment. It can be concluded that SMN tend to be deficient in some areas and vary spatially as influenced by soil intrinsic conditions and management, even at ward level.

Multifunctionality in maize production systems in the Mixteca Alta region of Oaxaca

Objective: To infer the role of multifunctionality in the milpa systems of the Mixteca Alta region of Oaxaca, Mexico. Design/Methodology/Approach: The methodological framework of the Multifunctionality Index of Agricultural Production Systems (IMSPA) was used, applying semi-structured interviews to producers. Results: The multifunctionality level of each evaluated systems was determined and the Milpa Intercropped with Fruit Trees (MIAF) showed the greatest multifunctionality and potential attributes for local development. Study Limitations/Implications: The resistance among producers to make changes in their plots usually leads to a refusal to participate and to mistrust this type of research. Findings/Conclusions: It is necessary to follow up on multifunctionality evaluations, since some systems are at a point where their functions can advance or regress.

The contribution of strong and weak ties to resilience: The case of small-scale maize farming systems in Mexico

CONTEXTThe relevance of social interactions (social ties) to farming systems' resilience is widely recognized. However, controversies exist around the contribution that farmers interacting with external actors (weak/bridging ties) versus with other farmers (strong/bonding ties) have in their resilience strategies through innovation. Farmers use different strategies to respond to their farming systems and contexts' particularities. Comparing the contribution of both strong and weak ties in different farming systems brings variety in resilience strategies. OBJECTIVETo generate evidence of the complementary contribution of social ties to resilience by comparing indexes associated with strong and weak ties from innovation networks of different farm types. METHODSThis paper applies an ego-centric social network analysis to farm units characterized by a farm typology to compare their strong/bonding and weak/binding ties contribution to innovation networks. It uses data from 29,796 farm units of maize smallholders in different regions from Central and Southern Mexico covering the gradient from commercial to subsistence farming. The analysis estimates two indexes based on actors' similarity/dissimilarity, that are External and Internal and Specialization Indexes. RESULTS AND CONCLUSIONSOur findings quantify differential contributions of strong versus weak ties to resilience strategies associated with innovation networks among different types of small-scale maize farmers. They demonstrate how differences among five farm types regarding farm resources access, maize production systems and farmers' social attributes influence their innovation networks. A gradient exists between farm types in their innovation network indexes regarding the contribution of strong versus weak ties. Commercial farmers, as the winners of the modernization process, have better access to resources and establish a wider variety of relationships with weak ties. However, interactions with other farmers are essential for technology adoption. In contrast, weak ties represented by institutions have a minor participation in innovation networks of diversified income and subsistence farm units. Strong ties dominate these farm types producing maize for consumption as part of their persistence strategies. Low-mechanized and elder family farm types, affected by geographic remoteness and population ageing processes, represent intermediate points in the gradient of farm resources and network indexes. SIGNIFICANCEJointly farm typology and social network approaches open new avenues to enhance farming system resilience. These approaches show how farmers establish their social interactions for innovation, creating specific combinations of strong and weak ties that are farm type specific. Diverse resilience strategies appear from these combinations involving not only adaptation but also persistence strategies that require further exploration.

Assessment of maize production system during the Covid-19 pandemic in Rwanda: Case study of Kigali City Region

The SARS-CoV-2 virus caused a major transformation in the food system globally including in Rwanda. This research identified and assessed the status and structure of the maize production system in the Kigali city region before and during the COVID-19 pandemic. The methods adopted for this study include both quantitative and qualitative methods using primary data obtained from the participants’ interview and focus group discussions, the secondary data were obtained from national institute of statistics of Rwanda (NISR). While production, processing, distribution and consumption are the four parts of the maize production system, the study only focused on the production system. The sample size for the study was 256 respondents who were maize production system actors from the Kigali city region. The study showed that before the COVID-19 pandemic, the prize of dried maize was significantly influenced by the cost of diammonium phosphate (DAP) (p=0.000), the source of the irrigating scheme (p=0.008), being a cooperative member (p=0.000) and marital status (p=0.002). During the pandemic, DAP (p=0.109) was absent at market due to lockdowns, and farmers did not access it. Maize farmers-built responses of resilience, persistence, adaptation, transformation, and persistence to encounter the consequences of the lockdowns. Innovative responses to shortage of maize- input stocks, and poor imports were presented, which represented 26.66% of resilient responses adopted by farmers. The innovative responses to labor shortage with farm workers` migration to their home provinces before and during the implementation of containment measures were 20%. Resilience built against the absence of extension services due to restricted movements was 13.33%. Reactions to restricted movement to and from fields, and adaptation to COVID-19 pandemic containing measures were 26.66 %, while reaction to the shortage of dried -maize at the market, which shortened the maize production cycle was 13.33%. Apart from maize production, more than half of the maize selling system were women 51.61%. Women in raw maize processing were 67.67% with a 100% level of university. Key words: COVID-19, food systems, city region, resilience, aflatoxin, maize production system, Kigali

Ammonia-oxidizing bacteria are the primary N2O producers in long-time tillage and fertilization of dryland calcareous soil

Human intervention in agriculture, such as tillage and fertilization, could result in major changes of N2O emissions that understanding the N2O emission mechanism is of great significance in reducing the N2O emissions of the agricultural system. In this work, we focused on the conventional tillage practice and straw return practice used in the spring maize production system of this region and compared them by the addition of 3,4-dimethylpyrazole phosphate (DMPP) to explore the N2O emission mechanism of the farmland. Compared with conventional farming, straw return significantly increased the N2O emissions from the soil. Soil pH had important effects on soil N2O emissions through its influence on the ammonia oxidizer community. In addition, DMPP was used to distinguish N2O emissions driven by ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB), and the results showed that AOB were the dominant factor regulating N2O emissions after receiving nitrogen from an external source in dryland farming calcareous soil. Through the analyses of soil AOB community composition and the aggregated boosted tree (ABT) model for N2O emissions, Nitrosospira Cluster 3a.2 was found to be the main driving force of soil N2O emissions in AOB communities. These findings will help better understand the physiochemical and biological mechanisms underlying the N2O emissions of agricultural soils and provide insight for reducing the negative impact of agricultural production systems on the ecological environment.

Foliage-Sprayed Nano-Chitosan-Loaded Nitrogen Boosts Yield Potentials, Competitive Ability, and Profitability of Intercropped Maize-Soybean

The progressive reduction of synthetic agrochemical fertilizers is one of the key factors in the shift from conventional agriculture to sustainable farming. Nitrogen (N) is the ruling element in the development of agricultural production, but its use in the mineral form or its excessive use causes several environmental issues. Since the release of N nanocomposites coincides with their uptake by crops, N loss reduces while enhancing plant uptake due to nano fertilizers application. Additionally, an intercropping legume with cereal as an eco-friendly pattern could improve and rationalize the nitrogenous inputs. Therefore, a two-year field trial was conducted to determine the efficacy of nano-chitosan-loaded N (CS-NNPs) for saving mineral N amounts applied in maize-based on maize-soybean intercropping and enhancing land productivity. Methods In a randomized split-plot design in three replicates, three intercropping patterns, in addition to the sole crops, and three N levels were implemented. Intercropping involved three intercrop configurations [planting maize rows (M) alternated with soybean rows (S) in patterns of 4M:2S, 2M:4S, and 3M:3S)], in addition to planting sole maize crop (SMC) and sole soybean crop (SSC). N fertilization treatments included adding 288 kg N ha−1 (MN100%) and two levels of CS-NNPs composite involving 216 kg N ha−1 + 2 foliar sprays of CS-NNPs (MN75% + 2CS-NNPs), and 144 kg N ha−1 + 3 foliar sprays of CS-NNPs composite (MN50% + 3CS-NNPs). Under the tested treatments, the agronomic traits, intercropping indices, and economic benefits were estimated. Results Findings revealed that the application of SMC × MN75% + 2CS-NNPs, followed by 4M:2S × MN75% + 2CS-NNPs showed the highest growth, biological yield, and grain yield of maize. The interaction of SSC × MN75% + 2CS-NNPs, followed by 2M:4S × MN75% + 2CS-NNPs resulted in the highest seed yield components, biological yield, straw yield, and seed yield of soybean. Application of 2M:4S × MN100%, 2M:4S × MN50% + 3NNPs, and 3M:3S × MN100% recorded the maximum total land equivalent ratio. While applications of 2M:4S × MN100%, 2M:4S × MN75% + 2CS-NNPs, and 3M:3S × MN100% achieved the highest land equivalent coefficient, land-use efficiency, area time equivalent ratio, and percent yield difference. Likewise, both interactions of 2M:4S × MN75% + 2CS-NNPs and 3M:3S × MN100% recorded the highest system productivity index. Better yield advantage of maize-soybean intercrop compared with the monocrop since total actual yield loss values were positive and higher than zero in all interactions of intercropping pattern × N fertilization. Fertilizing maize with MN50% + 3CS NNPs grown under the 2M:4S pattern had the highest positive aggressivity values. Conclusion The productivity shortfall accompanying the 25% N reduction was compensated by the application of CS-NNPs. Thus, N applied to the maize intercropped with soybeans can be rationalized. This undoubtedly has a good economic payoff for the maize growers with the conservation of the agricultural environment. In maize production systems, it is advisable to fertilize the plants using 216 kg instead of 288 kg nitrogen ha−1 when nano chitosan-loaded nitrogen composite twice (0.48 kg nitrogen ha−1) applied.

Can shallow-incorporated organic mulching replace plastic film mulching for irrigated maize production systems in arid environments?

Can shallow-incorporated organic mulching replace plastic film mulching for irrigated maize production systems in arid environments?

Conservation tillage and microbially mediated integrated phosphorus management enhance productivity, profitability and energy use efficiency of maize

AbstractSustainability of maize production systems is threatened by poor economic returns and resource intensiveness. Therefore, an experiment was conducted at the ICAR-Indian Agricultural Research Institute, New Delhi during 2016–17 to 2017–18 to assess the effect of tillage and microbial inoculantsintegrated phosphorus (P) management on productivity, quality, economic outcome and energy dynamics of maize. Three tillage practices viz., CT–R (conventional tillage with no residue), ZT–R (zero tillage with no residue) and ZT + R (zero tillage with wheat crop residue at 2.5 Mg/ha) were assigned in main plots and five P management practices viz., P1 (control–NK as per recommendation, but no P), P2 (17.2 kg P/ha), P3 (17.2 kg P/ha + PSB), P4 (17.2 kg P/ha + compost inoculants) and P5 (34.4 kg P/ha) were allocated in subplots in three times replicated split-plot design. The maximum grain yield (5.96 Mg/ha), protein content (9.13%), protein yield (546 kg/ha) and gross energy returns (209 × 103 MJ/ha) were recorded under ZT + R while higher benefit: cost ratio (B: C ratio – the amount of economic gain per unit investment) (1.53) and energy efficiency (12.5) was noticed under ZT–R. Among the P management practices, the application of 34.4 kg P/ha recorded the highest grain yield (6.45 Mg/ha), protein content (9.34%), protein yield (603 kg/ha), B: C ratio (1.65) and energy efficiency (10.1). The results suggested that the application of P at the rate of 34.4 kg/ha under ZT + R is an economically robust approach for the quality maize production in semi-arid region.

Valorization of nitrogen-rich melamine as a nitrogen source in the production of maize (Zea mays L.)

Maize is important for the biofuel and bio-based products. Building a clean maize production system could minimize the environment pollution from the N loss from the sloping land and achieve the industrial sustainable development. As a nitrogen-rich source, melamine could be used as a slow-release nitrogen (N) fertilizer, which provides a route for the recycling of melamine waste and the combatting of N loss from fertilizers. Model N release of melamine was compared with urea, sulfur(S)-coated urea via N loss in leaching column under intermittent leaching and under the ploughing fertilizer in the farmland soil. Only 7.12 % of the total nitrogen (TN) was lost from the 21 irrigation events, while the loss of TN from urea reached 77.28 %. TN from urea would be release totally in soil within 14 days in the ploughing fertilizer experiment, but 62 % of melamine was remained after 144 days. In order to evaluate the efficacy of melamine as an N fertilizer, plot experiments with an N rate of 180 kg ha-1 were carried out using pure melamine, urea and S-coated urea as well as mixed melamine/urea at 2:8, 1:1 and 7:3 by the N ratio. Melamine fertilization alone was unable to satisfy the N demand of maize, but the melamine/urea mixture (1:1) was comparable to the commercial S-coated urea in both years in terms of the grain yield (2217 kg ha-1 in 2019, 2368 kg ha-1 in 2020), total aboveground dry matter (5076 kg ha-1 in 2019, 4815 kg ha-1 in 2020), aboveground N uptake (36 kg ha-1 in 2019, 48 kg ha-1 in 2020), partial factor productivity of nitrogen (12.32 kg kg-1 in 2019 and 13.16 kg kg-1 in 2020) and net return (1474 USD in 2019, 1606 USD in 2020). Melamine accumulation in the maize grain measured from ELISA (enzyme-linked immunosorbent assay) ranged from 0.24 to 1.8 mg kg-1. The valorization of the melamine waste into N fertilizer by blending with urea was a possible way of reducing melamine pollution, alleviating N loss in hilly area and building a recyclable agriculture system.

Improving the net energy and energy utilization efficiency of maize production systems in the North China Plain

Energy analysis of agricultural production is essential to promote sustainable agricultural development. However, the current research on agricultural sustainability in the North China Plain (NCP) mainly focuses on improving grain yield and nitrogen utilization efficiency (NUE), while there are few studies on their energy utilization. This study evaluated the energy utilization characteristics of different yield and NUE category farms and three integrated agronomic approaches in the NCP based on farmer surveys and farm experiments. Compared with the average level of smallholder farms, the net energy (NE) and the energy utilization efficiency (EUE) of high-yield and high-NUE group farms increased by 17% and 22%, respectively, the NE of the high-yield and low-NUE group farms increased by 9%, but the EUE decreased by 12%. The control experiment showed that the NE and EUE achieved using high-yield and high-efficiency agronomic practice (HH) increased by 34% and 18% compared with achieved using traditional farmers' practices, respectively. In conclusion, there is a great opportunity to improve the NE and EUE of the maize production in the NCP by optimizing agronomic practices. Popularizing HH technology by improving agricultural technology extension services is of great significance for improving farmers’ EUE and promoting sustainable agricultural development.

The Combined Use of Liquid Fertilizer and Urease/Nitrification Inhibitors on Maize Yield, Nitrogen Loss and Utilization in the Mollisol Region

Nitrification inhibitor (NI) and urease inhibitor (UI) with fertilizer have the potential to reduce nitrogen (N) loss as well as improve grain yields. Urea-ammonium nitrate (UAN) solution as liquid fertilizer is superior to conventional solid nitrogen (N) fertilizer in terms of fertilizer efficiency, energy savings, environmental pollution reduction and economic benefits. However, comprehensive assessments of UAN with inhibitors from an environmental and agronomy perspective, including insights into the mechanisms of UAN with inhibitors, are lacking. In a field trial, three single-inhibitor and two double-inhibitor (DI) treatments were set to quantify the grain yield, the N losses and the N recovery efficiency of maize treated with urea supplemented with dicyandiamide (DCD), 3,4-dimethylpyrazole phosphate (DMPP) and N-(n-butyl) thiophosphoric triamide (NBPT). Compared with the UAN treatment, the supply of urease inhibitors reduced NH3 emission by 13.0% but increased N2O emission by 13.0%. The supply of nitrification inhibitors delayed the conversion of ammonium N to nitrate N and improved NH3 emission by 23.5-28.7%, but reduced N2O emission by 31.4% and significantly increased the maize yield by 21.3%. The combined use of NBPT and DCD were not compatible in UAN and cannot achieve the maximum potential for optimizing yields and reducing nitrogen losses. Considering the grain yield, the N use efficiency and the N losses, the combined use of NBPT and DMPP in maize production system significantly improved the grain yield and N use efficiency, as well as reduced N losses.

Efficiency of Resource Use in Rainfed Maize Production System by Small-Scale Farmers in Central Agricultural Zone of Cross River State, Nigeria

The study determined resource use efficiency in maize crop production by small-scale farmers in the Central Agricultural Zone of Cross River State Nigeria. It specifically examined the allocative efficiency of resources used by small-scale farmers in rainfed maize production in the area. Primary data were used to conduct the study. Statistical tools employed were multiple regression analysis and allocative efficiency index (AEI). The results of the multiple regression analysis revealed that the variables of farm size (x1), farm capital (x3), fertilizer (x4), farm credit (x6), extension service (x7), seeds planted (x8) had a positive relationship with the output of maize. The allocative efficiency index (AEI) of the various productive resources showed that farm size (x1), fertilizer (x3), and herbicides (x5) were found to be underutilized since their allocative efficiency index (AEI) was greater than one (1) and their marginal value product (MVP) were greater than their marginal factor cost (MFC) while Labour(x2) was over-utilized as the allocative efficiency index (AEI) was less than one (1). Based on these findings, the following recommendations were made; maize farmers should improve their use of productive resources such as land, capital, fertilizers, herbicide and seeds. Labour factor should be maximally utilized to create a favourable return to a unit of man day employed in maize production in the area.

Use of time series normalized difference vegetation index (NDVI) to monitor fall armyworm (Spodoptera frugiperda) damage on maize production systems in Africa

Fall armyworm (FAW) Spodoptera frugiperda (J.E. Smith), damage was monitored at a regional scale using time series data in Western and Southern African countries. The study employed the normalized difference vegetation index (NDVI) computed from Landsat 8 imagery using the Google Earth Engine (GEE) using image composites for the years 2013 to 2020 for the study areas. The index was then reclassified based on the NDVI threshold values into low, sparse, moderate, and dense classes. FAW prevalence data were then utilized to validate the correlation between the FAW infestation and NDVI values. FAW was associated with a decrease in vegetation productivity between the years 2016, 2017, and 2018 when the pest infestation was reported in the study areas. The validation results showed that there is a correlation between FAW infestation and NDVI (R20.83). Our study highlighted that NDVI can be used as a proxy to quantify pest damage to vegetation productivity.

Microorganisms, their residues, and soil carbon storage under a continuous maize cropping system with eight years of variable residue retention

Understanding the effects of agricultural management on microbial community dynamics and their relationships with soil carbon (C) properties is crucial to designing better management strategies (e.g., crop residue and tillage management) to enhance soil organic carbon (SOC) storage and other ecosystem services.In a no-till (NT) continuous maize production system in Northeast China, we combined living and dead microbial biomarker analyses, mid-infrared spectroscopy, and multivariate statistics to examine the effect of variable rates (0 %, 33 %, 67 % and 100 %) of maize stover retention for eight years on soil microbial community structure and the related change in soil C properties. We observed increases in the relative abundance of saprotrophic fungi (SF%) and the fungal to bacterial biomass ratio in the 33 % (NT33) and 67 % (NT67) retention treatments relative to complete stover removal (NT0). However, these increases were absent in the 100 % (NT100) stover return treatment suggesting a non-linear microbial community response to retention rate.Structural equation modeling revealed a negative relationship between dissolved organic carbon (DOC) concentration and the microbial stress indicator, as determined by ratios of cyclopropane phospholipid fatty acids to their precursors. Such negative relationship had a negative impact on SF%, subsequently influencing the fungal to bacterial necromass ratio and the aromaticity of soil C. A radar diagram area-based Soil Quality Index (SQI) approach showed that NT33 was associated with the highest SQI area, suggesting that low rates (33 %) of residue return had the greatest SOC sustainability through the enrichment of the labile DOC pool, efficient microbial growth and maintaining fungal necromass C persistence.This study adds to the mechanistic understanding of cellular trait-based microbial strategies with implications for soil C dynamics, and provides guidance for future management strategies in conservation agriculture.

Diversity of soil fertility management options in maize-based farming systems in northern Benin: A quantitative survey

Introduction: Maize-based production systems in Sub-Saharan Africa are largely based on family farming, which is characterized by low-input, nutrient-mining agriculture and practices. These systems usually promote soil degradation through loss of organic matter and erosion. The present study characterizes farms and main soil fertility management options in maize-based farming systems of the northern Benin.Methods: The study was conducted in the municipalities of Malanville, Banikoara and Bembèrèkè. We sampled randomly and interviewed 262 maize farmers, and the statistical analysis (distribution of means and frequencies, chi-square, ANOVA, etc.) was performed.Results and discussion: The results show that maize farming characteristics and socioeconomic conditions (land use and labor, production activities and land allocation, institutional arrangements on land, access to labor and capital, etc.) were diverse across locations and exhibited a wide variation within locations. Several practices were used for the management and sustainable maintenance of soil fertility in maize production systems in northern Benin: maize-legume intercropping, cotton-maize rotation, and mineral and organic fertilizers application. Most of farmers occasionally or regularly used mineral fertilizers (95.4%), followed by legume-cereal rotation/ intercropping (51.9%). Overall, 23.6% and 58.4% of farmers consistently used mineral fertilizer over the last 5 and 10 years, respectively. The amount of applied mineral fertilizer did not significantly vary between locations with an average (applied day after sowing, DAS) of 131.7 ± 13.7 (22 ± 8 DAS), 58.7 ± 9.6 (44 ± 5 DAS) and 164.7 ± 25.4 (38 ± 11 DAS) kg ha−1 for NPK, urea and Mix NPK + urea, respectively applied at, and days after sowing. Most farmers spread the fertilizer around the plants without covering with soil particles. Manure was applied exclusively to food crops through transporting and corralling (28.2%); and most farmers also used manure from their own livestock while few farmers used cattle corralling. Farmyard manure was mainly spread (100% of respondents) on the surface before plowing at the beginning of the rainy season. Maize farmers applied mineral fertilizer based on the level of initial soil fertility (naturally fertile or poor, degree of erosion etc.) and fertilizer purchase costs. Manure was not widely used as an alternative to chemical fertilizers; therefore, farmers need more strengthening and technical assistance on the production of organic fertilizers and manure storage. The findings are useful for policymakers on encouraging the successful implementation of sustainable soil fertility management strategies of maize-based farming systems in northern Benin.

Long-term manure application improves soil health and stabilizes carbon in continuous maize production system

Soil health lies at the core of a sustainable food production system. A comprehensive evaluation of different agronomic practices and their effect on soil health is essential to determine the best practices that support soil ecosystem services. However, it may take years or decades to observe measurable changes in soil health under varying management practices. The objective of this experiment was to evaluate the effects of long-term (>77 years) manure and inorganic nitrogen (N) fertilizer on soil health and determine the interrelationship among the measured soil bio-physicochemical indicators. The study also aims to understand the sustainability of the monocropping maize production system under long-term manure and inorganic N fertilizer management. The experiment site is the historic Knorr–Holden Plot, established in 1910 and continued till today. Over the years, the treatments were constant, with manure as the main factor and N rates as the sub-plot factor. Aligning with advancements in agronomic management, the rates of fertilizer and manure have been revised from time to time. Analysis of soil health indicators showed a significant effect of manure on different labile carbon (C) & N fractions, soil enzymes, and soil organic matter (SOM). Manure treatment improved C stabilization and reached a C equilibrium for management. Water holding capacity was significantly improved at wilting point and field capacity for manure treatment. Nitrogen treatments only affected soil pH, cationic exchange capacity (CEC), and phosphorus. Analysis of the interrelationship among soil health indicators showed SOM was determinative for C & N fractions and CEC. Soil organic carbon can be used as a proxy for soil total N (R2 = 0.98). Water extractable fractions of C and N were interrelated and can be used as determinative factors for each other. The results inform that a sustainable monocropping system can be maintained using long-term manure application, where soil health and organic carbon improve over time. The results also indicate that soil health measurement can be minimized to a few key indicators based on the functional interrelationship, which can broaden the adoption of soil health monitoring and measurement.

Crop Productivity, Nutritional and Economic Benefits of No-Till Systems in Smallholder Farms of Ethiopia

Smallholder maize and wheat production systems are characterized by high drudgery. On-farm trials were run for three seasons in Ethiopia. The study assessed the effect of 2 WT direct seeding and growing season on (1) soil quality, and (2) maize and wheat productivity, energy and protein gains, and gross margins, on smallholder farms in Ethiopia. For the wheat crop, the effect of different soil types and agroecological conditions on productivity was assessed. The treatments in paired plots were (i) conventional ploughing practice and (ii) no-till (NT). Soil properties, crop yield, nutrition gains and gross margins were determined. No-till improved soil properties in the short term. No-till produced 1210–1559 kg ha−1 grain, 18–29 GJ ha−1 energy and 121–194 kg ha−1 proteins, and generated 358–385 US$ ha−1 more than the conventional practice in the maize system. In the wheat system, no-till treatment had 341–1107 kg ha−1 grain, 5–16 GJ ha−1 energy and 43–137 kg ha−1 proteins, and generated 230–453 US$ ha−1 more than conventional practice. No-till can be more productive and profitable in the Ethiopian maize and wheat-based cropping systems.