摘要
【目的】农田土壤水热特性是决定作物生长发育和资源利用效率的关键因素,研究前茬处理方式对后茬农田土壤水热特性的影响,为试区高效麦玉轮作模式耕作措施的优化提供依据。【方法】在甘肃河西绿洲灌区,通过田间试验,研究前茬小麦秸秆不同处理方式和耕作措施(25 cm高茬收割立茬免耕—NTSS,25 cm高茬等量秸秆覆盖免耕—NTS,25 cm高茬等量秸秆翻压—TIS和传统低茬收割翻耕—CT)对后茬地膜覆盖栽培玉米农田土壤水热特性的影响。【结果】与CT相比,NTSS、NTS可提高后茬地膜覆盖玉米农田0—110 cm土层播种至苗期、拔节至大喇叭口期、吐丝至开花期的平均土壤含水量,分别高5.0%—7.8%、4.4%—5.4%和4.8%—7.1%,NTSS与NTS间的平均土壤含水量差异不显著;灌浆期内,NTS的土壤含水量比CT高4.7%,但NTSS与CT差异不显著,NTS具有保持后茬地膜覆盖玉米全生育期良好土壤水分含量的优势。NTSS、NTS减小了后茬地膜覆盖玉米吐丝期之前的耗水量,增大了吐丝期之后的耗水量,有效协调玉米生育前期与后期需水矛盾,以NTS的效果更突出。NTSS、NTS可有效改善后茬地膜覆盖玉米农田表层0—25 cm土壤的热量条件,NTS调控效应更强,2010年,NTS 8:00时的平均土壤温度比CT高0.76℃;2个试验年度内,NTS 14:00和18:00时的平均土壤温度比CT分别低3.67—3.87℃和1.19—1.30℃,说明前茬小麦秸秆免耕覆盖在昼夜低温期具有保温效应,而高温时具有降温作用。NTSS、NTS降低了后茬地膜覆盖玉米农田土壤积温,其中NTS处理玉米播种至拔节期、拔节至吐丝期、吐丝至灌浆末期的土壤积温比CT分别低67.1—76.2℃、29.3—50.5℃和46.7—75.3℃,降幅大于NTSS。从玉米不同生育时期平均大气-土壤温差可知,NTS在低温季有保持土壤温度的作用,在高温季节有相对降温的作用,是减少气温变化对玉米生长发育过度影响的重要机制。与CT相比,NTSS、NTS、TIS提高了后茬地膜覆盖玉米的籽粒产量,增产幅度为11.3%—17.5%,其中NTS两年籽粒产量最高,分别达到13 470和13 274 kg·hm-2,较TIS高5.6%—9.0%。【结论】前茬小麦秸秆免耕覆盖(NTS)是绿洲灌区地膜覆盖玉米适宜的前茬处理措施。
【Objective】 Soil water and temperature are key factors for determining crop growth and resource use efficiency, response of soil water and temperature of crops to previous straw usually plays an important role in establishing efficient cropping systems and optimizing tillage measures. 【Method】 A field experiment was carried out in typical oasis irrigation region in order to optimize soil water and temperature of rotated maize under different previous wheat straw treatments and tillage modes, including no tillage with 25 cm height of wheat straw standing（NTSS）, no tillage with 25 cm height of wheat straw covering（NTS）, tillage with 25 cm height of wheat straw was incorporated in the soil（TIS）, and conventional tillage without straw retention（CT）. 【Result】 The results showed that NTSS, NTS significantly increased soil water content by 5.0% to 7.8% in 0 to 110 cm soil layer from sowing to seedling stage, 4.4% to 5.4% from jointing to big flare stage, 4.8% to 7.1% from silking to flowering stage, but there was no significant difference between NTSS and NTS, and NTS increased by 4.7% at filling stage, compared with CT. In particular, the treatment on NTS had advantage on maintaining high soil water content at whole growth period of maize. NTSS and NTS decreased evapotranspiration of rotated maize under plastic film mulching before silking stage, but evapotranspiration was increased after silking stages, which effectively coordinated water demand contradiction of maize growth at early and late stage, the effect of NTS was the best. NTSS and NTS optimized soil temperature of rotated maize under plastic film mulching, and the effect of NTS was obvious. NTS had higher soil temperature by 0.76℃ at eight o＇clock in 0 to 25 cm soil layers in 2010, but lower by 3.67 to 3.87℃ at fourteen o＇clock and 1.19 to 1.30℃ at eighteen o＇clock, in 2010 and 2012, which indicate that NTS had effects on preservating soil temperature at low temperature stage at the day and night, and decreasing soil temperature at the high temperature stage. Meanwhile, NTSS and NTS reduced soil accumulated temperature in rotated maize field, and the reduction of NTS was more significant, it reduced by 67.1 to 76.2℃ from sowing to jointing stage, 29.3 to 50.5℃ from jointing to silking stage, and 46.7 to 75.3℃ from silking to late-filling stage, compared with CT. However, according to the value of difference between air and soil temperatures, NTS had the effect of maintaining soil heat in low temperature season and reducing soil temperature in high temperature season, which is an important regulation mechanism on growth and development of maize through reducing the excessive influence resulted from the temperature change. The grain yield of maize was 11.3% to 17.5% higher in the three straw returning treatments than that in CT check, NTS exhibited the most significant effect on high yield, reached 13 470 and 13 274 kg·hm^-2 in two study years, which were higher than TIS by 5.6% to 9.0%. 【Conclusion】 The results show that NTS treatment can be recommended as the best previous wheat straw treatment for optimizing soil moisture and temperature of rotated maize at oasis irrigation areas.
出处
《中国农业科学》
CAS
CSCD
北大核心
2016年第15期2898-2908,共11页
Scientia Agricultura Sinica
基金
国家自然科学基金(31360323)
国家公益性行业(农业)科研专项(201503125-3)
国家"十二五"科技支撑计划(2012BAD14B10)
关键词
玉米
秸秆还田
地膜覆盖
土壤温度
土壤水分
maize
straw returning
plastic film mulching
soil temperature
soil moisture
