| Summary: | Nutrient omission trials were conducted on farmers’ fields in 2020 and 2022. The experiment included nine treatments: three treatments with nitrogen (N), phosphorus (P), potassium (K), sulfur (S), zinc (Zn), and boron (B) as individual, blended, and compound fertilizer; four treatments with the omission of K, S, Zn, or B; NP-only; and control without any nutrient. Treatments were arranged in a randomized complete block design with three replications under foot slope (FS), mid-slope (MS), and hillslope (HS) positions. Results showed that soil properties and maize yield significantly varied among landscape positions, with substantial soil fertility and yield increasing trends from HS to FS position. The highest grain yield (6.18 t ha−1) was recorded at the FS position, with the respective yield increments of 14% and 16% compared to the MS and HS positions. Applying all nutrients in blended form resulted in the highest grain yield (6.52 t ha−1), but it was not significantly different from yields of compound and individual fertilizer forms. Applying all nutrients in blended form increased grain yield by 7.4% and 264.2% compared to the NP-only and the control, respectively, indicating the non-significant effects of K, S, Zn, and B on yield. Overall, N and P are the most yield-limiting nutrients for maize production, and site-specific NP fertilizer recommendations targeting landscape position are required to enhance nutrient use efficiency and sustainably intensify maize yield. Developing site-specific fertilizer recommendations advisory will enhance nutrient use efficiency, increase and sustain yield, and benefit farmers while improving soil and environmental quality.
Plain Language Summary
This paper reports research targeting different nutrient sources on maize yield and soil properties under different landscape positions.Our understanding of the management of plant nutrients under different landscape positions in tropical farming systems is still limited, where soil fertility depletion and nutrient mining are key constraints to increased and sustainable crop yield because of low soil organic matter content, low nutrient and water retention capacity, and nutrient losses. Optimizing fertilizer use efficiency at a landscape level is an efficient approach for reducing soil erosion and nutrient losses, reducing environmental pollution, and improving food and nutrition security while sustaining crop yield. Several fertilizer trials were piecemeal and mostly on suitable landscapes. Hence, this research may contribute information to research and development, and enhance our scientific understanding of landscape features and their impact on soil properties and crop yield.
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