秸秆还田配施化肥对土壤肥力及鲜食甘薯产量和品质的影响

通过2017和2018两年的田间试验研究了小麦秸秆还田和施肥对土壤肥力、酶活性以及鲜食甘薯产量和品质的影响。试验设5个处理:秸秆不还田+常规施肥(CK)、小麦秸秆半量还田+常规施肥(50%S)、小麦秸秆全量还田+不施肥(100%S-F)、小麦秸秆全量还田+常规施肥(100%S)、小麦秸秆全量还田+常规施肥+150 kg·hm^-2氮肥(100%S+N)。结果表明:秸秆还田施肥处理显著提高了土壤中的有效磷、碱解氮、总氮和有机质含量,显著提高了土壤过氧化氢酶、碱性磷酸酶、脲酶和蔗糖酶活性。秸秆还田施肥处理均显著提高了薯块产量、单薯鲜重和商品薯率,其中50%S处理下薯块产量最低。2年的秸秆还田处理下,薯块产量和商品薯率均在100%S处理下最高。2年的秸秆还田施肥处理总体上提高了甘薯的淀粉和蛋白质含量,但100%S和100%S+N处理均降低了甘薯还原糖和可溶性糖含量。可见,小麦秸秆全量还田的效果优于半量还田,与常规施肥配合下薯块产量和商品薯率最高,但影响食用口感,实际生产中可适当减少氮肥用量。

Effects of straw returning and fertilization on soil fertility and yield and quality of edible sweetpotato

Two-year field experiments were conducted in 2017-2018 to examine the effects of wheat straw returning and fertilization on soil fertility and enzyme activities, as well as the yield and qua-lity of edible sweetpoato. There were five treatments, including conventional fertilization+zero straw (CK), conventional fertilization+50% straw returning (50%S), zero fertilization+100% straw returning (100%S-F), conventional fertilization+100% straw returning (100%S), conventional fertilization+100% straw retuning+150 kg N·hm^-2 (100%S+N). The treatments of straw returning and fertilization significantly increased the contents of available phosphorus (P), hydroly-zable nitrogen (N), total N, and organic matter in soils, and increased the activities of soil catalase, alkaline phosphorylase, urease, and invertase. The storage root yield, single root fresh weight and commodity potato rate were significantly increased under the treatments of straw returning and fertilization. The storage root yield was the lowest under the treatment of 50%S. After two years of straw returning, storage root yield and commodity potato rate were the highest under the treatment of 100%S. In general, the contents of starch and protein in sweetpotato were increased after two years of straw returning and fertilization, but the contents of reducing sugar and soluble sugar were decreased under 100%S and 100%S+N treatments. Our results suggested that straw returning in full quantity was better than straw returning in half quantity. The storage root yield and commodity potato rate was the highest under the combination of full quantity straw returning and conventional fertilization, with the taste of sweetpotato being changed. Thus, the amount of nitrogen fertilizer should be appropriately reduced in actual practice.