Matching N supply for yield maximization in salt-affected wheat agri-food systems: On-farm participatory assessment and validation

Driven by the UN-SDGs of achieving food security and agricultural sustainability, it remains more challenging in degraded ecosystems to simultaneously improve the crop performance without creating unintended favour for excessive fertilization and associated environmental consequences. We assessed the N-use pattern of 105 wheat-growers in sodicity affected Ghaghar Basin of Haryana, India, and then experimented upon to optimize and identify indicators of efficient N use in contrasting wheat cultivars for sustainable production. The survey results revealed that majority of farmers (88%) have increased their reliance on N nutrition (∼18 % extra N), and even extended their duration of N scheduling (12-15 days) for better plant adaptation and yield insurance in sodicity stressed wheat; albeit to a greater extent in moderately sodic soils applying 192 kg N ha^-1 in 62 days. The participatory trials validated the farmers' perception of using more than the recommended N in sodic lands. This could realize the transformative improvements in plant physiological [higher photosynthetic rate (Pn; 5 %) and transpiration rate (E; 9 %)] and yield [more tillers (ET; 3 %), grains spike^-1 (GS; 6 %) and healthier grains (TGW; 3 %)] traits culminating in ∼20 % higher yield at 200 kg N ha^-1 (N₂₀₀). However, further incremental N application had no apparent yield advantage or monetary benefits. At N₂₀₀, every additional kilogram of N captured by the crop beyond the recommended N improved grain yields by 36.1 kg ha^-1 in KRL 210 and 33.7 kg ha^-1 in HD 2967. Further, the varietal differences for N requirements, with 173 kg ha^-1 in KRL 210 and 188 kg ha^-1 in HD 2967, warrants the need of applying balanced fertilizer dose and advocate revision of existing N recommendations to cope up the sodicity induced agricultural vulnerability. Principal Component Analysis (PCA) and correlation matrix showed N uptake efficiency (N_UpE) and total N uptake (TNUP) as the highly weighted variables illustrating strong positive association with grain yield, and potentially deciding the fate of proper N utilization in sodicity stressed wheat. Key insights suggested that combining participatory research with farmers' knowledge and local perspective could be decisive in better integration of technologies, and serving to adapt the real-time soil sodicity stress and sustaining wheat yields with economized farm profits.

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.

Crops and farmers' response to application of fecal sludge derived - Fortifer™ in different agro-ecological zones in Ghana

Fecal sludge (FS)-derived fertilizer material, Fortifer™ was used in farmers' field to cultivate different crops under varying soil and agro-climatic conditions in Ghana. The aim was to (1) create awareness among smallholder farmers for widespread use of Fortifer™ (2) observe the response of crops to Fortifer™ application by farmers in different agro-ecological zones (3) obtain farmers feedback on the FS-derived product to enhance further dissemination across the country. In total 95 farmers in six locations participated in the farmer-led pilots. Fortifer™ containing up to 3.0% nitrogen, 3.6% phosphorus, 1.3% potassium and 44.3% organic matter was applied to tomato, rice, maize and pepper in comparison to inorganic fertilizers at recommended rates. Subsequently, farmers' perception of, and willingness to use the product were studied. Crop yield was significantly higher (p ≤ 0.05) in the Fortifer™ plots compared to the inorganic fertilizer plots for all the selected crops. Yield was 12% higher for tomato, 27% for rice and maize and 30% for pepper under the Fortifer™ plots. Farmers indicated that, nutrient content was the most important factor they consider when making fertilizer purchasing decision.