Ridge-furrow planting with black film mulching over ridge and corn straw mulching over furrow enhancing summer maize's growth and nutrient absorption

Abstract: Precipitation shows frequent and great variability in arid and semi-arid region in northwest China where crop production is generally dependent on rainfall, therefore, rainwater harvesting has been widely used in northwest China for its capacity of conserving soil water, increasing crop production and improving water use efficiency. The main purpose of this study was to explore the effects of different rainwater harvesting patterns on growth and nutrient absorption and utilization of summer maize, and organic matter content and nitrate nitrogen distribution in soil. To achieve these goals, a 2-year field experiment was carried out in 2013 and 2014 at the Key Laboratory (108°24′E, 34°20′N) of Agricultural Soil and Water Engineering in Arid and Semiarid Areas sponsored by Ministry of Education, at Northwest A&F University. Five kinds of treatments were conducted using a complete randomized block design with three replicates. They were ridge-furrow planting with transparent film mulching over ridge only (M1), ridge-furrow planting with corn straw mulching over furrow only (M2), ridge-furrow planting with transparent film mulching over ridge and corn straw mulching over furrow (M3), ridge-furrow planting with black film mulching over ridge and corn straw mulching over furrow (M4), and a control treatment of ridge-furrow planting without mulching both over ridge and furrow (CK). The accumulation of shoot dry mass, root growth (including root length, root surface area, root volume and total root dry weight), nutrient accumulation (including nitrogen, phosphorus, and potassium) and yield of summer maize and organic matter content and NO3--N distribution in soil under different rainwater harvesting patterns were measured. In addition, nutrient use efficiency, nutrient uptake efficiency and partial fertilizer productivity among treatments were compared. The results showed that the aboveground biomass of summer maize matched the Logistic curve over time. Mulching treatments had larger theoretical values of aboveground biomass, longer durations of rapid accumulation period, and stronger root system than that of CK. And M4 had the highest level among the four mulching treatments. The results also indicated that root system mainly distributed in the depth of 0-40 cm and it tended to be shallower under mulching treatment. The rainwater harvesting pattern had impact on soil nutrients as well. For example, the content of organic matter under straw mulching (M2, M3 and M4) was significantly (P<0.05) higher than that of CK and M1. M3 and M4 had a greater infiltration depth of nitrate nitrogen than others and the depth peaked to 200 cm, which could prevent nitrate nitrogen from deep percolation. The nutrient accumulation among plant organs was highest in fruit, followed by leaf, stem and root, and the amount of potassium in stems was slightly larger than that in leave. Compared with CK, the mulching treatments remarkably increased not only nitrogen, phosphorus, and potassium uptake efficiency, but also the partial factor productivity of fertilizer. Among the 4 mulching treatments, M4 had the highest partial factor productivity of fertilizer, which was averagely increased by 8.37%, 14.93% and 3.74% compared with M1, M2 and M3 in the 2 years, respectively. In this study, taking plant growth, nutrient absorption, fertilizer use efficiency and soil fertility maintenance into consideration, the dual-mulching, especially the ridge-furrow planting with black film mulching over ridge and corn straw mulching over furrow could be an appropriate method for summer maize cultivation in drought area. The results above would provide valuable information for selecting efficient rainwater harvesting pattern to realize high and stable yield and sustainable agriculture development in semi-arid regions of China.