Organic Amendments Influence Soil Water Depletion, Root Distribution, and Water Productivity of Summer Maize in the Guanzhong Plain of Northwest China

Li-Li Zhao,Huan-Jie Cai,Lu-Sheng Li,Chao Zhang,Xiao-Hu Shi

doi:10.3390/w10111640

Abstract

Organic amendments improve general soil conditions and stabilize crop production, but their effects on the soil hydrothermal regime, root distribution, and their contributions to water productivity (WP) of maize have not been fully studied. A two-year field experiment was conducted to investigate the impacts of organic amendments on soil temperature, water storage depletion (SWSD), root distribution, grain yield, and the WP of summer maize (Zea mays L.) in the Guanzhong Plain of Northwest China. The control treatment (CO) applied mineral fertilizer without amendments, and the three amended treatments applied mineral fertilizer with 20 Mg ha−1 of wheat straw (MWS), farmyard manure (MFM), and bioorganic fertilizer (MBF), respectively. Organic amendments decreased SWSD compared to CO, and the lowest value was obtained in MBF, followed by MWS and MFM. Meanwhile, the lowest mean topsoil (0–10 cm) temperature was registered in MWS. Compared to CO, organic amendments generally improved the root length density (RLD) and root weight density (RWD) of maize. MBF showed the highest RLD across the whole soil profile, while MWS yielded the greatest RWD to 20 cm soil depth. Consequently, organic amendments increased grain yield by 9.9–40.3% and WP by 8.6–47.1% compared to CO, and the best performance was attained in MWS and MBF. We suggest that MWS and MBF can benefit the maize agriculture in semi-arid regions for higher yield, and WP through regulating soil hydrothermal conditions and improving root growth.

Highlights

The intensification of crop cultivation and livestock leads to a large increase in the production of straw and animal manure in semi-arid regions of China and elsewhere [1,2,3]
Wang et al [13] confirmed that maize water productivity increased by 3–8% based on the improvement of grain yield in organic manured soils over four years, soil water content decreased in the 50–150 cm soil layer
It is essential to assess the effects of various organic amendments on soil water conditions and crop water productivity for adjusting the optimum organic amendment practices to local conditions

Summary

Introduction

The intensification of crop cultivation and livestock leads to a large increase in the production of straw and animal manure in semi-arid regions of China and elsewhere [1,2,3]. Summer maize (Zea mays L.) is a widely cultivated crop in this area, with an annual production of 3.4 billion kg of grains (Shaanxi Provincial Bureau of Statistics, http://www.shaanxitj.gov.cn/). In this region, organic amendments from plant residues or livestock manure have been used, with the primary goal of improving soil water conditions and crop water productivity. It is essential to assess the effects of various organic amendments on soil water conditions and crop water productivity for adjusting the optimum organic amendment practices to local conditions

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