垄覆黑膜沟覆秸秆促进夏玉米生长及养分吸收

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

针对中国西北干旱半干旱地区降水年际变率大、年内分配不均衡的气候特点,探究更为有效的农田集雨模式以实现农业的稳产高效和可持续发展。通过2 a田间试验,对比研究了不覆盖(CK)、垄覆白膜沟不覆盖(M1)、垄不覆盖沟覆秸秆(M2)、垄覆白膜沟覆秸秆(M3)和垄覆黑膜沟覆秸秆(M4)5种集雨模式对夏玉米生长、养分吸收利用及土壤有机质含量和硝态氮分布的影响。结果表明,夏玉米地上部生物量随生育进程的动态变化符合Logistic生长模型。处理M4地上部生物量理论最大值最高,快速生长持续时间最长,根系最发达;夏玉米根系主要分布在0~40 cm土层,且覆盖条件下,根长分布呈浅根化趋势。覆盖秸秆可有效提高土壤有机质含量;不同集雨模式下土壤硝态氮峰值所在土层深度存在差异,其中处理M3和M4硝态氮入渗较深,但其峰值仍保持在200 cm土层内,不会产生深层渗漏。夏玉米各器官中养分累积量表现为果>叶>茎>根(其中K素累积量为茎略大于叶)。2 a中各覆盖处理夏玉米植株氮、磷和钾吸收效率及肥料偏生产力均显著(P<0.05)高于对照。其中处理M4的平均肥料偏生产力分别较处理M1、M2和M3提高8.37%、14.93%和3.74%。综合分析,全程微型聚水覆盖(M3和M4)尤其是垄覆黑膜沟覆秸秆可较好的促进植株生长及养分吸收,同时能维持地力,具有较大的增效潜力。该研究可为干旱半干旱地区改善集雨种植模式、提高农业生产力提供参考。

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 NO-3-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.