地表覆盖方式对辣椒水分利用效率、果实品质及氮素分布的影响

研究了地表覆盖方式对辣椒 (Capsicum anmuum L.)水分利用效率、品质、叶片硝酸还原酶活性及植株和土壤中氮素分布的影响。结果表明，覆盖可增加辣椒整个生育期土壤水分含量。覆盖地膜和覆盖秸秆+地膜比其他地表处理方式能显著增加辣椒的产量和经济收入，提高产量水分利用效率和经济水分利用效率。覆盖可显著降低耕作层（0—20 ㎝）土壤硝态氮含量，且随着土层深度的增加，硝态氮含量显著降低，但对各土壤铵态氮含量无显著影响。对品质而言，覆盖地膜处理辣椒果实pH、维生素C含量显著高于其它处理，且其电导率、阳离子交换量和硝酸盐含量显著低于其他处理。覆盖可增强叶片硝酸还原酶活性，降低叶片中的全氮含量，显著降低每百千克产量氮肥吸收量。从提高辣椒的品质、环境安全、肥料利用和经济效益各因素考虑，生产中辅以科学的水分管理，覆盖地膜和覆盖秸秆+地膜是可行的地表覆盖方式。

Influences of soil mulching approaches on WUE,fruit quality and nitrate distribution of capsicum

The effects of soil mulching approaches on water use efficiency, fruit quality and leaf nitrate reductases activity of capsicum (Capsicum anmuum L.), and as well as plant and soil nitrate allocation were studied in a green house environment. There were four treatments in the study, namely, control(CK), straw mulching(T₁), plastic film mulching(T₂), and straw and plastic film combined mulching (T₃). The results show that soil water contents are increased in the capsicum growth period for the three mulching practices, and plastic film mulching and straw and plastic film combined mulching can get high capsicum yields, water use efficiency of yield and economic water use efficiency compare to the other two treatments. Soil nitrate-N contents of the tillage layer (0-20 cm) are significantly decreased under the mulching treatments, the high the soil depths, the lower the soil nitrate contents. However, soil ammonium-N contents are not significantly affected by the mulching practices. Vitamin C content and pH value of capsicum fruit are increased under the plastic film mulching, while electricity conductivity, cation exchange capacity and nitrate content of the soil are decreased. Nitrate reductases activity of leaves are increased under the mulching practices, while total N content of leaves is decreased, and the N absorption amount per 100 kg yields is reduced significantly. In agriculture production, helped with scientific water management, plastic film mulching, and straw and plastic film combined mulching are feasible mulching practices to enhance capsicum fruit quality, environment security, fertilizer use efficiency and economic benefit.