The Potential for Improving Rice Yield and Nitrogen Use Efficiency in Smallholder Farmers: A Case Study of Jiangsu, China

Abstract

Closing yield (YG) and nitrogen use efficiency (NUE) gaps amongst smallholder farmers are critical to ensuring food security and environmental sustainability. Here we report a comprehensive analysis of a data set derived from farm-surveys and previously published studies in a typical high N input area of China. Using scenario analysis, farmers from both sources were divided into four rice production levels to assess the YG and NUE of smallholder farmers. Farm surveys showed that rice yield and partial factor productivity of applied N (PFPN) averaged 8273 kg ha−1 and 23.1 kg kg−1 at regional-scale, with a potential increase of 21–43% and 33–52%, respectively. A wide variation in yield and PFPN across different types of farmer was observed. Optimized N management significantly narrowed YGs by 3.7% and PFPN gap by 63.5% on average based on the published literature. Multiple factors, including excessive N rates, small rice planting area (0.33 ha), the aging (51 years old) and low education level (6 years of education) of the major labor force, can partly explain causes of yield and NUE gaps. These findings provide farm-based evidence that centralized management, good agronomy plus advances in knowledge and technologies are essential for future agricultural development.

Low fertilizer inputs do not adversely affect yield or performance of Indica hybrid rice

“…A PFP N of 41.1 kg kg -1 of irrigated rice was reported previously on a national scale in China (Xu et al, 2018). PFP N values of 50 kg kg -1 and above are generally considered to be achievable with good management (Dobermann and Fairhurst, 2000;Xie et al, 2020). In this study, the PFP N s of early season rice were 37.82 and 42.24 kg kg -1 in 2017, and 26.06 and 38.34 kg kg -1 in 2018 under CUF and COF treatments, respectively, whereas the PFP N s of late season rice were 51.85 and 60.49 kg kg -1 in 2017, and 36.73 and 49.14 kg kg -1 in 2018 under CUF and COF treatments, respectively.…”

“…Previous studies have suggested that small farm and smallholder management are key causes of low agricultural productivity worldwide (Ju et al, 2016). In China, the rice planting area per household was on an average of 0.33 ha, and 60 % of farmers had < 0.3 ha of planting area (Xie et al, 2020). Most farmers lacked the knowledge of required application of N-fertilizer to obtain optimal amounts of grain production.…”

“…The HI was calculated as the ratio of the filled grain dry weight to the total above ground biomass. The NUE, defined as the yield produced per unit of N applied (Cassman et al, 1996;Fageria et al, 2005), was approximate using an N partial factor productivity (PFP N , kg rice grain per kg N applied) since it integrates fertilizer input, inherent soil N supply capacity, and achieved yield, and as such is the broadest measure of NUE (van Noordwijk et al, 2014;Xie et al, 2020). PFP N = Grain yield with N application / N application rate.…”

Improving Yield and Water Productivity of Rainfed Summer Maize in Smallholder Farming: A Case Study in Hebei Province, China

“…The gaps in the yield and WP between the HYHW and LYLW groups were 2186 kg ha −1 and 12.5 kg ha −1 mm −1 , respectively, which were attributed to the uneven fertilizer application rate, soil fertility, crop management, and educational qualification. Xie et al [33] also reported big yield gaps between different groups of famers in rice production. The yield and WP were affected by multiple factors.…”

Ways to Improve the Productivity of Oasis Agriculture: Increasing the Scale of Household Production and Human Capital? A Case Study on Seed Maize Production in Northwest China

“…Chandra conducted a comparative analysis on the agricultural production efficiency of different farm scales in Nepal, and found that farms too large or too small are not conducive to the realization of maximum agricultural production efficiency [22]. Ángeles et al examined the production efficiency of small family farms as the main decision-making unit of horticulture in southeastern Spain from a micro level [23] [28]. Pangapanga-Phiri Innocent et al studied the reasons why drought-affected farmers' adoption of climate-saving agricultural practices and their impact on the efficiency of corn production technology.…”