Surface Fertigation Practices for Smallholder Farmers in the North China Plain

The North China Plain (NCP) stands as a densely populated region vital for agriculture, sustaining a large population through intensive farming practices. However, the reliance on irrigation and fertilization in the region has led to inefficiencies in water and nutrient use, compromising the sustainability of agriculture and contributing to environmental degradation. To address these challenges, the focus of this study is on optimizing water and fertilizer management, particularly through surface fertigation. This method involves applying fertilizers dissolved in irrigation water to enhance water use efficiency (WUE) and nitrogen use efficiency (NUE). Each section explores different facets of surface fertigation, aiming to improve the uniformity of fertilizer distribution in irrigation water, subsequently enhancing crop yields while reducing water and fertilizer leaching.

A participatory study in the People's Victory Canal Irrigation District revealed farmers' satisfaction with current practices but identified obstacles to adopting more efficient technologies. Challenges included a lack of knowledge about advanced fertigation systems, constraints of small-scale farming, and high implementation costs. Tailored guidelines grounded in empirical evidence and considering socio-economic factors are crucial for overcoming these challenges. An experimental approach in subsequent sections evaluated surface fertigation practices tailored to NCP farmers' fields. Traditional methods showed low field application efficiency and uneven distribution of water and fertilizers. The WinSRFR model aided in understanding these practices, leading to proposed methods for enhancing application efficiency and distribution uniformity. Optimal irrigation depths for wheat and maize were identified to be 95 mm and 80 mm, respectively. Continuing with field experiments and modeling, the study analyzed the impact of irrigation and fertigation practices on crop yield, WUE, NUE, and nitrogen loss. The findings emphasized the need for integrating optimized irrigation and fertigation strategies for sustainable crop production and minimized nitrogen loss. The viability of transitioning smallholder farmers in the NCP to organic fertilizer application through surface fertigation was explored. A 50% organic fertilizer ratio was found to balance maintaining crop yield and minimizing nitrogen leaching. The study advocated for compensation to offset additional costs for farmers adopting organic fertilizers.

In conclusion, the study highlights inefficiencies in current irrigation and fertilization practices in the NCP and suggests surface fertigation as a promising solution. Refining practices, such as adjusting irrigation depth and fertigation scheduling, can significantly enhance WUE, NUE, and mitigate environmental impacts. The research underscores the importance of tailoring solutions to local conditions and farmer preferences, emphasizing the need for government support and incentives to facilitate the adoption of sustainable practices. The research methodology reflects a commitment to evidence-based approaches, utilizing participatory tools, field experiments, and simulation models to assess and refine fertigation strategies. Looking ahead, successful implementation of improved practices relies on understanding and engaging with the local farming community, addressing their concerns, enhancing their knowledge, and providing cost-effective solutions. The research suggests a pathway towards sustainable agriculture in the NCP, emphasizing the need for a comprehensive approach considering both environmental and socio-economic factors.