Effects of organic amendment incorporation on maize (Zea mays L.) growth, yield and water-fertilizer productivity under arid conditions.

Land degradation is one of the world's most pressing environmental problems and a constraint to agricultural production. Application of diverse organic amendments provides a management strategy to compensate for soil organic carbon depletion and reduce land degradation. The objective of this study was to investigate the effects of different organic amendments on soil properties, crop growth and water-fertilizer productivity under arid conditions. Soil in a maize field located in the upper reaches of Yellow River was amended with sheep manure compost and maize stover respectively. Five different application rates (2, 4, 6, 8 and 10 t ha-1) were carried out for the compost, and maize stover (6 t ha-1) combined with two different decomposing agents were implemented. Main component of the decomposing agent was Bacillus subtilis and Trichoderma harzianum , respectively. Soil aggregation and physical-chemical properties were generally improved with the incorporation of compost and maize stover. The addition of compost and maize stover reduced the bulk density and increased the field capacity, soil organic matter, aggregate stability and the saturated hydraulic conductivity. The emergence rate and maize growth properties improved in the organic materials amended plots. However, soil properties and crop growth non-monotonically varied with application rate of compost. The addition of different decomposing agents in maize stover amended plots did not show significant impact on most soil properties, but improved soil nutrient status, crop growth and yield with different levels compared with maize stover alone. Comprehensive analysis of yield, crop water productivity and partial factor productivity for nitrogen, incorporation of compost at a rate of 5–6 t ha-1 or 6 t ha-1 maize stover combined with Bacillus subtilis was recommended as a proper strategy in loamy soil under arid conditions. • The application of compost and maize-stover improved soil aggregation and physical-chemical properties. • Soil aggregation, saturated hydraulic conductivity and crop productivity non-monotonically vary with the application rate of compost. • Organic amendment improved water-fertilizer productivity through changes in soil aggregation. • Compost showed better performance on soil properties and crop productivity than the same amount of maize stover under arid conditions. [ABSTRACT FROM AUTHOR]