For years, the agricultural community has faced the challenge of feeding a growing global population while minimizing environmental impact. Traditional methods often rely on high rates of nitrogen fertilizer, which, while boosting crop yields, can lead to reduced resource efficiency and soil degradation. This creates a pressing need for more precise and sustainable farming strategies. A recent study published in the Journal of Agriculture and Food Research by authors Hui Cao, Yingpan Yang, Yang Gao, Junming Liu, Shoutian Ma, and Aiwang Duan, addressed this by examining how different organic soil amendments, when combined with varying nitrogen levels, affect wheat production and soil health in a semi-arid region of China.

The research, conducted over three years, used a split-plot design to test three different nitrogen levels (120, 240, and 360 kilograms per hectare) and four organic amendments: straw (used as a control), chicken manure, mushroom residue, and biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More. The study’s primary goal was to find the optimal combination that would enhance crop productivity and resource use efficiency while simultaneously improving soil fertility. The results were clear: a moderate nitrogen application of 240 kg per hectare, combined with either mushroom residue or biochar, was the most effective strategy.

The findings highlight the significant impact of organic amendments on soil health, a critical factor for long-term productivity. Soil aggregate stability, measured by mean weight diameter (MWD), was notably improved in treatments that included biochar, mushroom residue, and chicken manure. Compared to the control treatment of straw, biochar application increased MWD values by an impressive 37.78%, while mushroom residue and manure increased them by 27.01% and 18.26%, respectively. This improvement in soil structure is essential for better water infiltration and aeration, which supports healthier plant growth.

These positive effects on soil health directly translated into higher crop yields and more efficient resource use. The study found that wheat yield was at its highest with the moderate nitrogen rate of 240 kg per hectare. When comparing the different organic amendments at this rate, biochar was the standout performer, increasing wheat yield by 7.23% compared to straw. Mushroom residue also performed exceptionally well, boosting yield by 4.56%. Water use efficiency (WUE) and partial factor productivity of nitrogen (PFPN) followed a similar trend, with biochar application increasing WUE by 4.17% and PFPN by 10.16% over straw. Mushroom residue also showed strong gains, increasing WUE by 1.99% and PFPN by 3.36%.

A key metric in the study was the Soil Fertility Index (SFI), a comprehensive measure of overall soil health. Among all treatments, the combination of 240 kg N per hectare and mushroom residue resulted in the highest SFI. The three-year average showed that mushroom residue application at this moderate nitrogen level significantly increased SFI by 18.08% compared to the straw treatment. This finding underscores that mushroom residue is a particularly effective organic amendment for improving the overall quality and health of the soil.

The study’s results provide a scientific basis for optimizing fertilization strategies, especially for semi-arid regions like the North China Plain. The traditional practice of using high nitrogen rates (often 300 kg per hectare) has been shown to be inefficient and harmful to soil. The new findings suggest that farmers can achieve better results by combining a more moderate nitrogen rate with organic amendments like biochar or mushroom residue. This approach not only boosts crop productivity but also enhances soil structure, nutrient availability, and overall fertility. The research shows that shifting away from solely relying on nitrogen fertilizers toward a more integrated approach with organic materials is a viable and beneficial path for sustainable agriculture.

Source: Cao, H., Yang, Y., Gao, Y., Liu, J., Ma, S., & Duan, A. (2025). Organic amendments combined with moderate nitrogen rate significantly enhance soil fertility and crop productivity. Journal of Agriculture and Food Research, 23, 102211.