不同耕作措施对西北绿洲灌区冬小麦农田土壤呼吸的影响

在西北绿洲灌区多年田间定位试验基础上,研究了免耕秸秆覆盖(NTS)、免耕不覆盖(NT)和传统耕作(T)3种耕作措施下冬小麦农田土壤呼吸变化特征及其对土壤温湿度的敏感性。结果表明,3种耕作措施土壤呼吸速率日变化和生育期变化呈单峰曲线。免耕秸秆覆盖处理土壤呼吸速率日峰值出现在15:00,免耕不覆盖和传统耕作处理出现在14:00。3种耕作措施土壤呼吸速率生育期峰值出现在冬小麦开花期。从冬小麦返青至成熟,免耕秸秆覆盖和传统翻耕处理土壤呼吸平均速率分别较免耕不覆盖处理高43.01%和33.33%。3种耕作措施下土壤呼吸对土壤温度的敏感性(Q₁₀)依次为NT＞NTS＞T,敏感性为1.93~3.00;3种耕作措施下土壤呼吸对土壤含水量不敏感。说明在西北绿洲灌区,不同耕作措施下冬小麦农田土壤呼吸主要受耕层土壤温度的控制。

Effect of different tillage treatments on soil respiration of winter-wheat farmland in oasis irrigated area Northwest China

Based on a long-term field experiment,the effects of no-tillage with wheat stubble mulching(NTS),no-tillage without wheat stubble mulching(NT) and conventional tillage(T) on soil respiration of winter wheat were studied in oasis irrigated area,Northwest China.The results showed that soil respiration rates appeared in single-peak curve during diurnal and seasonal changes under three tillage treatments.The maximum of diurnal soil respiration rate under NTS treatment occurred at 15: 00,but those of NT and T treatments occurred at 14:00.The peak value of seasonal soil respiration rate under three tillage treatments occurred at anthesis stage of winter wheat(early June).The average of soil respiration rates of NTS and T treatments were 43.01% and 33.33% higher than that of NT treatment,respectively.The sensitivity of soil respiration to soil temperature(Q10) was 1.93-3.00 and was NT>NTS>T.Soil respiration was not significantly sensitive to soil water content.It was suggested that soil respiration under different tillage was mainly controlled by soil temperature in this area.