Increasing farm size to improve energy use efficiency and sustainability in maize production

Influences of crop diversification on yield, resource use efficiency, and environmental footprint in farmland landscapes in intensive farming

Enhancing crop diversification in intensive fields has the potential to increase crop yield and reduce environmental footprint. However, these relationships at the landscape scale remained unclear in intensive farming. Addressing this gap, this paper aims to elucidate how crop yield, resources use efficiency (RUE), and environmental footprint (EF) vary with crop diversification levels in the North China Plain. Management practices, including crop pattern, field size, and agronomic inputs, were collected for 421 landscapes of 1 × 1 km subplots using Sentinel-2 and Landsat-8 images and survey. The results showed that, at the landscape scale, energy and fertilizer contributed over 53 %, and 37 % of the carbon footprint, respectively. N fertilizer constituted >98 % of the nitrogen footprint. P fertilizer accounted for over 80 %, while electricity comprised >13 % of the phosphorus footprint. Compared with simplified landscapes, diversified landscapes exhibited several significant features: 1) 56 % reduction of the area ratio of winter wheat-summer maize double crop pattern (WM), 2) a significant decrease in field size, 3) the decreased use of total NPK fertilizers at 32 %, 30 %, and 30 %, respectively, 4) the increased inputs of irrigation water, diesel, electricity, pesticide and labour at 21 %, 19 %, 21 %, 77 %, and 92 %, respectively. Although yield could be reduced at 33 % when transforming simplified landscapes into moderately diversified ones, they increased with the further promotion of crop diversification. Thus, the diversified landscapes could achieve a balance in yield, RUE, and EF to enhance sustainability, whereas simplified landscapes can similarly achieve a balance to benefit productivity. We emphasize the viable potential of diversified landscapes to enhance sustainable agricultural development by optimizing crop composition. This analysis offers pioneering evidence of landscape-scale agronomic and environmental performances of crop diversification.

Assessing agricultural greenhouse gas emission mitigation by scaling up farm size: An empirical analysis based on rural household survey data

Agriculture is a major contributor to greenhouse gas (GHG) emissions. Farm size affects agricultural production inputs and thus has impacts on agricultural GHG emissions. However, the effects and mechanisms behind this are still unclear. In this paper, we identified the effects and mechanisms of farm size on agricultural GHG emissions, based on survey data about over 20,000 rural households in China from 2009 to 2016. Firstly, we calculated the agricultural CO2, CH4, and N2O emissions using the life-cycle analysis (LCA). Secondly, the impacts of farm size on GHG emissions intensity were explored with a fixed effect model, based on the long-term rural household survey data. Finally, the mechanisms were tested by the mediation effect model. The results showed that a 1 % increase in farm size, on average, could reduce the GHG emissions intensity of rural households by 0.245 % from 2009 to 2016. The mechanism analysis showed that the larger farm size reduced GHG emissions intensity mainly by reducing the non-fixed input intensity and raising fixed input investment. By identifying the impacts and mechanisms of farm size on agricultural GHG emissions, this paper aims to provide insights for policymakers to achieve China's goal of reaching carbon neutrality by 2060.

Identifying synergistic solutions for the food-energy-water nexus via plastic film mulching cultivation

Food security, water scarcity, and excessive fossil energy use pose considerable challenges to sustainable agriculture. To understand how rain-fed farming systems on the Loess Plateau, China, reconcile yield increases with ecological conservation, we conducted an integrated evaluation based on the denitrification-decomposition (DNDC) model, agricultural statistics data using the Food-Energy-Water (FEW) nexus indicator. The results showed that maize yields with ridge-furrow plastic film mulching (PFM) were 3479, 8942, and 11,124 kg ha-1 under low (50 kg N ha-1), medium (200 kg N ha-1), and high (350 kg N ha-1) nitrogen (N) fertilizer rates, respectively, and that PFM increased yield and water use efficiency (WUE) by 110-253 % and 166-205 % compared to using no mulching (control, CK), respectively. Plastic film mulching also increased net energy (126-436 %), energy use efficiency (81-578 %), energy productivity (100-670 %), and energy profitability (126-994 %), and nitrogen fertilizer, compound fertilizer, and diesel fuel consumption by agricultural machinery were the main energy inputs. The PFM system reduced water consumption during the maize growing season and the green water footprint and gray water footprint decreased by 66-74 % and 44-68 %, respectively. The FEW nexus indicator, based on a high production at low environmental cost scenario, was greater under the PFM system and had the widest spatial distribution area at the medium-N application rate. Among the environmental factors, the nexus indicator was negatively correlated with precipitation (-0.37), air temperature (-0.36), and the aridity index (-0.36), but positively correlated with elevation (0.17). Our results suggest that the PFM system promotes resource-saving while increasing yields and moves dryland agriculture in an environmentally friendly direction, thus promoting the sustainable development of agroecosystems.

Energy budgeting and carbon footprint of different wheat-rice cropping systems in China

Wheat-rice cropping system in China, characterized by smallholder with conventional practice, is energy- and carbon-intensive. Cooperative with scientific practice is a promising practice to increase resource use while reducing environmental impact. However, comprehensive studies of the energy and carbon (C) budgeting of management practices on the actual field-scale production under different production types are lacking. The present research examined the energy and C budgeting of smallholder and cooperative using conventional practice (CP) or scientific practice (SP) at the field scale level in the Yangtze River Plain, China. The SPs and cooperatives exhibited 9.14 % and 6.85 % and 4.68 % and 2.49 % higher grain yields over the corresponding CPs and smallholders, respectively, while maintaining 48.44 % and 28.50 % and 38.81 % and 20.16 % higher net income. Compared to the CPs, the corresponding SPs reduced the total energy input by 10.35 % and 7.88 %, and the energy savings were primarily attributable to reductions in fertilizer, water, and seeds through the use of improved techniques. The total energy input in the cooperatives was 11.53 % and 9.09 % lower than that for the corresponding smallholders due to the mechanistic enhancements and improved operational efficiency. As a result of the increased yields and reduced energy inputs, the SPs and cooperatives ultimately increased energy use efficiency. The high productivity attributed to increased C output in the SPs, which increased C use efficiency and the C sustainability index (CSI) but decreased the C footprint (CF) over the corresponding CPs. The higher productivity and more efficient machinery of cooperatives increased the CSI and reduced the CF compared to the corresponding smallholders. Overall, the SPs coupled with cooperatives were the most energy efficient, C efficient, profitable and productive for wheat-rice cropping systems. In the future, improved fertilization management practices and integration of smallholder farms were effective means for developing sustainable agriculture and promoting environmental safety.

Occurrence profiling and environmental risk assessment of veterinary antibiotics in vegetable soils at Chongqing region, China

Veterinary antibiotics (VAs) are emerging contaminants in soils as they may pose high risks to the ecosystem and human health. Identifying VAs accumulation in soils is essential for assessing their potential risks. Therefore, we investigated the distribution of VAs in soils from vegetable fields and evaluated their potential ecological and antimicrobial resistance risks in the Chongqing region of the Three Gorges Reservoir area, China. Results indicated that twenty-six species of VAs, including nine sulfonamides (SAs), seven quinolones (QNs), four tetracyclines (TCs), four macrolides (MLs), and two other species of VAs were detected in soils, with their accumulative levels ranging from 1.4 to 3145.7 μg kg^-1. TCs and QNs were the dominant VAs species in soils with high detection frequencies (100% TCs and 80.6% for QNs) and accumulative concentration (up to 1195 μg kg^-1 for TCs and up to 485 μg kg^-1 for QNs). Risk assessment indices showed that VAs (specifically SAs, TCs, and QNs) in most vegetable soils would pose a medium to high risk to the ecosystem and antimicrobial resistance. Mixture of VAs posed a higher risk to soil organisms, antimicrobial resistance, and plants than to aquatic organisms. Modeling analysis indicated that socioeconomic conditions, farmers' education levels, agricultural practices, and soil properties were the main factors governing VAs accumulation and environmental risks. Farmers with a high educational level owned large-scale farms and were more willing to use organic fertilizers for vegetable production, which eventually led to high VAs accumulation in vegetable soil. These findings would provide a reference for sustainable agricultural and environmental production under the current scenario of chemical fertilizer substitution by organic products and green agricultural development.

How do carbon emissions, economic growth, population growth, trade openness and employment influence food security? Recent evidence from the East Africa

East Africa has a substantially greater rate of food insecurity than other regions of the world. Scenarios of climate change and other macroeconomic variables are important contributors to food insecurity in East Africa. Using data spanning from 1990 to 2020, this study looked into the influence of carbon dioxide (CO₂) emissions, economic growth, population growth, trade openness, and agricultural employment on food security in the East Africa. The fully modified ordinary least square (FMOLS) and dynamic ordinary least square (DOLS) models were used in this study. The heterogeneous panel cointegration test's findings indicated that the study variables have an equilibrium long-term connections. The estimation findings from the FMOLS and DOLS models showed that an increase in CO₂ emissions increases food security in the East Africa over the long term. According to other findings, long-term food security is positively impacted by economic expansion, population growth, trade openness, and employment in agriculture. However, trade openness has a detrimental long-lasting effect on food security. Future research directions, research limitations, and policy implications are discussed.

Farm size, farmers' perceptions and chemical fertilizer overuse in grain production: Evidence from maize farmers in northern China

China's agriculture is characterized by small-scale farms whose overuse of chemical fertilizers is widespread. This makes it a key challenge for China to sustainably feed its growing population. In this study, we investigate the role of farm size in maize production and how it relates to farmers' fertilizer application strategies. We use cross-sectional survey data of 774 maize-producing farms in northern China, and develop a conceptual framework that links farm production, on-farm resources, the socio-economic characteristics of the households and farmers' knowledge and perceptions as a whole. We use linear and logistic regression models to show that despite the recent declines in fertilizer application rates, excessive fertilizer use persists in maize cultivation in northern China. Farm size has a negative effect on chemical fertilizer use and a positive effect on maize yield. In addition, farmers on large farms achieve significantly higher knowledge scores in terms of fertilizer use and maize cultivation. They are also more likely to attend agricultural training and adopt scientific fertilizer use techniques. Increased farm size, participation in training, better farming knowledge, and having a family member as a village cadre are associated with farmers' decisions to reduce the use of conventional fertilizers. The key to achieving more sustainable grain production in China is to increase farm size, while enhancing the effectiveness of agricultural extension and promoting scientific fertilization techniques. Social networks within and between villages should also be utilized for knowledge transfer. In addition, cooperation between research institutions and fertilizer companies should be further emphasized to improve the accessibility of regionally adjusted formulated fertilizers.

Getting ahead of the pandemic curve: A systematic review of critical determining factors for innovation adoption in ensuring food security

The imminent threat to food security requires immediate intervention toward ensuring societal sustainability especially in combating the pandemic. The rapid spread of COVID-19 cases has caused concern for food security. A recent outlook report produced by Food Agricultural Organization and World Food Programme (FAO-WTP) highlights that there are at least 20 countries that are faced with a looming threat of food availability between the period of March-July 2021. Other factors that pose a significant threat to food security include climate change and natural disasters which could significantly reduce the yield. It is hence imperative to gain an in-depth understanding of factors that influence farmers' choices in innovation adoption for increased yield. A line of research has been conducted across the globe on new technology adoption and effect of innovation that aims to increase productivity and yield. This study examined the key factors, that lead farmers to the adoption of new technology and innovation, reported in studies over the past 15 years. PRISMA-P (Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols) was employed based on the SCOPUS and Web of Science database. In creating the main dataset, a protocol was developed in advance to document the analysis method. Several inclusion (eligibility) and exclusion criteria were set to select related articles from a total of 2,136 papers. The thematic and content analyses were subsequently performed on 392 research articles. The findings indicate 4 over-arching segments, and 12 major determinants, that comprise 62 associate determinants. The paper concludes with the identification of critical factors for innovation adoption amongst farmers.

Towards a sustainable food production: modelling the impacts of climate change on maize and soybean production in Ghana

The Ghanaian economy relies heavily on maize and soybean production. The entire maize and soybean production system is low-tech, making it extremely susceptible to environmental factors. As a result, climate change and variability have an influence on agricultural production, such as maize and soybean yields. Therefore, the study's ultimate purpose was to analyze the influence of CO2 emissions, precipitation, domestic credit, and fertilizer consumption on maize and soybean productivity in Ghana by utilizing the newly constructed dynamic simulated autoregressive distributed lag (ARDL) model for the period 1990 to 2020. The findings indicated that climate change enhances maize and soybean yields in Ghana in both the short run and long run. Also, the results from the frequency domain causality showed that climate change causes maize and soybean yield in the long-run. These outcomes were robust to the use of the ordinary least squares estimator and the impulse response technique. The findings show that crop and water management strategies, as well as information availability, should be considered in food production to improve resistance to climate change and adverse climatic circumstances.

Land Fragmentation, Technology Adoption and Chemical Fertilizer Application: Evidence from China

Although it has been widely recognized that land fragmentation has increased chemical fertilizer application, little is known about the role of technology adoption in mitigating these adverse effects. To empirically examine the relationship between land fragmentation, technology adoption and chemical fertilizer application, we developed a mediation model. We applied our analysis to a survey data set encompassing 1388 farm-level samples collected in 14 Chinese provinces in 2019. Our study demonstrated that land fragmentation can not only directly increase chemical fertilizer application but also indirectly increase it by hindering the adoption of agricultural mechanization technologies (AMT’s) and soil testing fertilization technologies (STFT’s). Both are recognized as potent drivers of fertilizer use reductions. Moreover, the adoption of information and communications technologies (ICT’s) can help mitigate the negative effects of land fragmentation on technology adoption, thus reducing chemical fertilizer application intensity (CFAI). However, the direct effects of land fragmentation on CAFI was unaffected by ICT’s. Our findings suggest that ICT’s have revolutionized farmer recognition, promotion and adoption of agricultural technologies by increasing awareness and diffusion of agricultural technology information.