Planting practices with nutrient strategies to improves productivity of rain-fed corn and resource use efficiency in semi-arid regions

摘要

Nutrients and water are major factors that affect corn production and resource use efficiency, as well as the soil water storage and WUE in dryland cultivation regions. The development of water saving cultivation practices is essential instead of relying on irrigation resources. However, the interactive effects of cultivation practices and nitrogen application for maize crop in semi-arid regions have not yet been clear. Therefore, in 2015 and 2016, we studied the interactive effect of three cultivation practices (plastic mulching ridges with furrow planting (RF), furrow planting with soil crust ridges (SC), traditional cultivation (CK)) under three different nitrogen rates 300, 200 and 100 kg ha(-1). The results indicated that the RF system enhanced seeding emergence, prolonged the seed filling duration, and improved biomass and N accumulation than the CK treatment. under the 200 kg N ha(-1) with RF system can increase soil water storage and enhance plant development, reduce ET rate (14.1%), as a result increased grain yield (30.4%), thereby achieving a higher WUE (52.0%), RUE (30.7%) and agronomic efficiency (11.9%) than the CK treatment with 200 kg N ha(-1). As well, RF system significantly improved N uptake efficiency (NupE, 58.5%), N fertilizer productivity (NfP, 33.1%), N use efficiency (NUE, 28.6%) and N harvest index (NHI, 6.1%), in comparison with CK treatment. A high 300 kg N ha(-1) under different cultivation practices considerably reduced NupE, NfP and NUE, and the optimum N rate for the corn must be less than 300 kg ha(-1) to enhance the NupE, NfP and NUE. Therefore, in dryland cultivation areas, the RF system with 200 kg N ha(-1) should be a proper water-saving strategy for achieving higher corn productivity in the dryland cultivation regions.