Impact of Organic and Chemical Nitrogen Fertilizers on the Crop Yield and Fertilizer Use Efficiency of Soybean–Maize Intercropping Systems

Abstract

The effect of the mixture (1:1) of chemical and organic nitrogen (N) fertilizer on crop yield quality and N fertilizer use efficiency remains elusive. A nitrogen field experiment was conducted in the growing seasons of 2020 and 2021 to investigate the effects of the mixture of chemical and organic N fertilizer on the crop yield, crop quality and nitrogen fertilizer use efficiency in a maize–soybean intercropping system in China. Four treatments applied at 150 kg N ha−1 were used: no nitrogen fertilizer (CK), chemical N fertilizer (ChemF), mixture (1:1) of chemical and organic N fertilizer (ChemF + OrgF) and organic N fertilizer (OrgF). The results showed that the yield and aboveground N accumulation of both soybean and maize increased with the application of fertilizer. The ChemF + OrgF treatment had lower maize and soybean seed yields than for ChemF treatment, but higher than the other two treatments in both years, and the maize yield of the (ChemF + OrgF) treatment was significantly higher (14.9%) in 2021 than 2020. Yields were significantly positively correlated with aboveground N accumulation and fertilizer use efficiency, measured using the nitrogen partial productivity (NPP), nitrogen agronomic efficiency (NAE) and nitrogen fertilizer recovery rate (NFRR). The protein content tended to increase and the oil content tended to decrease under (ChemF + OrgF) applications in soybeans. The (ChemF + OrgF) treatment had the lowest starch content in maize. There was no significant difference in the nitrogen harvest index among treatments, while the NPP, NAE and NFRR were the highest for the application of chemical N fertilizer and significantly decreased with the addition of organic N fertilizer. We conclude that the mixture (1:1) of chemical and organic N fertilizer increased the seed yield and quality of maize, but only the seed yield of soybean.

Assessing the impact of biochar and nitrogen application on yield, water-nitrogen use efficiency and quality of intercropped maize and soybean

“…The released nutrient rate may not coordinate with soybean protein formation but coordinate with fat formation (Liu et al., 2021). The other possible explanation for the result is that soybean protein and oil content may be mainly determined by the gene ( Lin et al., 2022 ). In addition, soil microorganisms and environment also have an impact on crop quality ( Studnicki et al., 2016 ; Kundel et al., 2020 ).…”

Multifaceted Ability of Organic Fertilizers to Improve Crop Productivity and Abiotic Stress Tolerance: Review and Perspectives

“…Moreover, Lin and co-authors found that the protein concentration was increased with organic and chemical fertilizers, while the oil contents were decreased with the same treatment. These authors also noted that the combined use of chemicals and organic fertilizers resulted in a reduction in their starch contents, and there was no significant impact of this combination on the nitrogen harvest index (ratio of N accumulated in grain to N accumulated in grain plus straw) [82]. The use of organic fertilizers substantially increased the seed quality parameters and nitrogen use efficiency (NUE) of plants [83,84].…”

“…However, some authors found no advantage of chemical and organic fertilizing in increasing nutrient uptake and the NUE [119]. Other authors also found that the combined use of chemicals and organic fertilizers increased the N partial productivity (NPP), N agronomic efficiency (NAE), fertilizer use efficiency and N fertilizer recovery rate (NFRR) in maize and soybean [82,120]. The slow and gradual release of nutrients and the increase in organic matter with organic fertilizers is linked with an improved NUE [121][122][123].…”

Relative Importance of Barriers and Levers to Intercropping Systems Adoption: A Comparison of Farms and Co-Operatives

“…For the farmer, the interest is twofold: (i) a reduction of mineral nitrogen inputs and thus of production costs, and (ii) a less polluting production since the mineral nitrogen usually used in conventional agriculture is highly leachable. The competitiveness of the cereal on nitrogen uptake ends up capturing the residual mineral nitrogen of the previous crop, while the symbiotic fixation of atmospheric nitrogen by the legume provides a resource for its own need and completes the missing needs of the complementary plant [21][22][23][24].…”