Effects of No-till with Stubble Mulch on Seed Emergence of Crops under Irrigation in Hexi Irrigation District,Gansu
Conservation tillage is generally believed to reduce runoff and evaporation,increase rainfall infiltration,improve soil structure and fertility,reduce soil erosion and restrain dust storm by leaving crop residues on soil surface.It has been widely adopted in many countries.No-till with stubble mulch is one kind of conservation tillage.A study was conducted to evaluate the effect of no-till with stubble mulch,irrigation on seed germination and emergence at Shiyang river and Heihe river valley of Hexi Corridor in Gansu Province,China.There was a two sites: one site was at Liangzhou district of Hexi Corridor,the other site was Ganzhou district.There were 3 tillage treatments and 5 irrigation regimes,replicated 3 times.The three tillage treatments are conventional tillage with bare ground (CTB),conventional tillage with straw incorporated (CTS) and no-till with straw mulch (NTS).Irrigation regimes used were 600,975,1,350,1,725 and 2,100m3/ha. Results showed that NTS greatly improved soil moisture content by 60% in winter fallow compared with CTB.However,NTS decreased the soil heat transmission ability and increased sunlight reflection,resulting in low soil temperature during sowing period in spring.The soil temperature of NTS was 3～5℃ lower than that of CTB.It was observed that some seeds were rotten due to the low temperature and wet soil.As a result,NTS decreased the rates of seed germination and emergence greatly.For the pea crop,results showed that tillage had greater effect on seedling density than irrigation norm.There was a significant difference in seedling density between tillage treatments.The seedling density of CTB,CTS and NTS was 149,130 and 123 × 104 seedlings/m2 respectively,with significant difference between CTB and CTS or NTS,but no difference NTS and CTS.Accordingly,the yield and water use efficiency of NTS decreased considerably.It is suggested that NTS was not suitable in Hexi irrigation region.Shallow tillage before sowing probably can improve seed emergency.There were no significance differences between storage irrigation norms.Therefore,the storage irrigation norm can be reduced to 750m3/ha in order to save water.
NTS no-till storage irrigation soil temperature seeding density
Shi Jionglin Zhang Jinxia Jing Ming
Department of Water Resources Engineering,Gansu Agricultural University,Lanzhou,Gansu,70070,China Department of Water Resources Engineering,Gansu Agricultural University,Lanzhou,Gansu,70070,China Yellow River Institute of Hydraulic Research,Xinxiang,Henan,453003,China
国际会议
南京
英文
110-114
2006-08-16（万方平台首次上网日期，不代表论文的发表时间）