Straw mulch decreased N fertilizer requirements via regulating soil moisture and temperature to improve physiology, nitrogen and water use efficiency of wheat

Abstract

The infrequent rainfall caused drought prone condition particularly in semi-arid regions of China, where most of the precipitation occurs in summer season. Thus, the summer rainwater conservation is very important for winter wheat (Triticum aestivum) production. Therefore a 2-year field experiment was conducted on straw mulch along with N fertilizer to improve physiology, nitrogen use efficiency (NUE), wheat yield, and water use efficiency (WUE). Maize (Zea mays) was a rotated crop after wheat, and therefore maize straw mulch (S1, 0 kg ha−1; S2, 4500 kg ha−1; S3, 9000 kg ha−1) was in the main plots, and N fertilizer (N1, 0 kg ha−1; N2, 192 kg ha−1 (80%); N3, 240 kg ha−1 (100%)) was in the sub plots. The interaction of S3N3 and S3N2 produced 59.2% and 43.8% higher net photosynthesis and enhanced its characteristics at booting stage compared with that of S1N1. Higher SPAD values (49.1 and 41.0%) and leaf area (85.6 and 61.0%) measured with S3N3 and S3N2 treatments at booting stage compared with S1N1. Both S3N2 and S3N3 had increased wheat N-uptake (91 and 103%, respectively) compared to S1N1. While S3N3 and S3N2 enhanced soil moisture conservation, NUE (19.7 and 22.8%), and WUE (47.2 and 47.2%) with the improvement in the growth yield of wheat compared to S1N1. Higher 7604 kg ha−1 of wheat grain yield was obtained from interaction of S3N2. Therefore, interaction of S3N2 is a viable approach for improving the winter wheat crop performance in term of NUE, WUE and wheat yield for semiarid areas in China.