地膜覆盖对热带地区南瓜产量及土壤碳氮的影响

Effects of plastic film mulching on pumpkin yield and characteristics of soil carbon and nitrogen nutrients in tropical areas

地膜覆盖技术在热带地区海南岛广泛应用,以探究不同颜色地膜覆盖对冬季南瓜产量、品质和土壤碳氮养分活性状态的影响为目标,为改善地膜覆盖技术下土壤肥力提供科学依据。2020年设置地膜覆盖田间试验,5个处理3次重复,处理为对照、白色、黑白双色、黑色、银黑色地膜覆盖处理。研究结果表明,黑色、银黑色地膜覆盖可显著提高南瓜产量、品质,单果平均重超过4 kg,产量分别为112.20、102.45 t/hm^(2),单果重、单产、去瓢鲜重、去瓢干重均达到对照4倍以上,可溶性糖约为其他处理的3倍。黑膜、银黑膜覆盖降低土壤有机质、全氮含量,增加土壤活性养分含量,提高土壤活性碳氮比。经过一个南瓜生育期,其高活性有机质分别为4.67、5.20 g/kg,约为其他处理的4倍,碱解氮分别为61.37、77.12 mg/kg,极显著高于其他处理。黑色、银黑色地膜覆盖可导致土壤有机质、全氮含量有所降低,迅速积累活性有机质、碱解氮含量从而显著提高热带地区海南岛南瓜产量。

Plastic film mulching is widely used in tropical Hainan island.The objective of this study was to explore the effects of different colors of plastic film mulching on pumpkin yield,quality and soil carbon and nitrogen activity status in winter and to provide scientific basis for improving soil fertility under plastic film mulching.In 2020,a field experiment of plastic film mulching was conducted in Haikou,Hainan province.Five treatments with three repetitions were set up,including no plastic film mulching control treatment,white,black-white,black and silver-black plastic film mulching treatments,to study the effects of different colors plastic film mulching.The results showed that black and silver-black mulching significantly improved the yield and quality of pumpkin.The average weight of each fruit in black and silver-black mulching treatments exceeded 4 kg,and the yields were 112.20 t/hm^(2) and 102.45 t/hm^(2),respectively.The single fruit weight,yield per unit,fresh fruit weight and dry fruit weight of the two groups of treatments were 4 times greater than those of the control treatment.The soluble sugar was about 3 times that of other treatments.Black film and silver-black film mulching reduced soil organic matter and total nitrogen content,increased soil active nutrient content,and improved the ratio of soil active carbon to nitrogen.After a pumpkin growth period,the highly active organic matter of the soil treated with black and silver-black plastic film was 4.67 and 5.20 g/kg,which was about 4 times that of other treatments,and the alkali-hydrolyzed nitrogen was 61.37 and 77.12 mg/kg,respectively,extremely significantly higher than other treatments.Black and silver-black plastic film mulching can reduce the total soil nutrient organic matter and total nitrogen content,and rapidly accumulate active organic matter and alkali-hydrolyzed nitrogen content,thereby significantly improving the yield of pumpkin in tropical Hainan island in winter.