摘要
开沟播种是一种可显著提高地下滴灌春玉米出苗率的新型播种方式,为了优化该技术模式,该文通过两年田间试验分析了地下滴灌玉米出苗率与灌水后种子处土壤有效饱和度(effective saturation)的关系,并基于HYDRUS-2D构建了地下滴灌开沟播种土壤水分运动模型,以90%玉米出苗率为前提,研究了不同土质和土壤初始含水率条件下3个技术参数——开沟深度、滴灌带埋深和灌水量对种子处土壤有效饱和度的影响。结果表明:1)出苗率随土壤有效饱和度线性递增,土壤有效饱和度不小于0.77时,出苗率超过90%;2)地下滴灌开沟播种HYDRUS-2D模型模拟精度较高,模拟得到的土壤有效饱和度随开沟深度增大而增大,随滴灌带埋深增大而减小;3)满足土壤有效饱和度为0.77所需的出苗水灌水量随土壤黏粒含量、土壤初始含水率和开沟深度增大而减小,随滴灌带埋深增大而增大。当表层土壤初始含水率为40%田持~60%田持时,开沟深度每增加5 cm,砂壤土的出苗水灌水量减小15~20 mm,粉壤和粉黏土的出苗水灌水量减小6~18 mm;滴灌带埋深由30 cm增大到35 cm时,砂壤土的出苗水灌水量增大16~21 mm,粉壤和粉黏土的出苗水灌水量增大4~14 mm。不同埋深和开沟深度下,当表层土壤初始含水率由40%田持增大到60%田持时,砂壤土的出苗水灌水量减小9~14 mm,粉壤和粉黏土的出苗水灌水量减小9~19 mm;4)综合考虑土壤质地、玉米根系分布、机械作业、耗能、耕作深度和土壤水深层渗漏以及土壤初始含水率,玉米地下滴灌适宜的滴灌带埋深为30~35 cm,开沟深度为10~15 cm,灌水量范围为25~67 mm。农业生产者可以根据当地实际情况对以上3个技术参数进行合理配置。
Subsurface drip irrigation（SDI） is an advanced water-saving irrigation method. Alternate row/bed planting is a sowing technique with a 10 cm deep trapezoidal furrow; seeds are then sown in 5 cm deep soil below the furrow bottom. It can significantly improve the germination of spring maize under subsurface drip irrigation. To optimize this technology, 2-year field experiments were performed in Chifeng, Inner-Mongolia, China to study the relationship between the emergence rate of spring maize and soil effective saturation of soil at the location of the seeds after different pre-emergence irrigation amounts from 15 to 60 mm. A HYDRUS-2D model was established to obtain soil effective saturation when seed germination rate reached 90% and then to investigate effect of furrow depth, dripline depth, and irrigation amount in the conditions of different soil texture and initial water content on soil effective saturation in order to obtain best technique parameters combination for seed germination. The irrigation amount was 15, 25, 45 and 60 mm; the furrow depth was 0 and 10 cm; the dripline depth was30 cm. The germination rate was obtained when the seed germination kept stabilized. The results showed that the maize germination rate increased linearly with soil effective saturation（R2=0.70, P〈0.01）. The HYDRUS-2D model simulation results had a high agreement with the measured soil water content with the root mean square error of 0.024-0.035 cm3/cm3）.The soil effective saturation was not less than 0.77 for 90% of germination rate. The simulation results showed that the soil effective saturation increased with the increase of furrow depth and decreased with the increase of dripline depth. The required irrigation amount to meet the effective saturation of 0.77 decreased with the increase of soil clay content due to the larger hydraulic conductivity of the fine textured soil. The required irrigation amount to meet the effective saturation of 0.77 also decreased with the increase of initial soil water content and fur
作者
莫彦
李光永
蔡明坤
王丹
徐新涵
边新洋
Mo Yah Li Guangyong Cai Mingkun Wang Dan Xu Xinhan Bian Xinyang(College of Water Resources ＆ Civil Engineering, China Agricultural University, Beij＇ing 100083, China Irrigation and Drainage Department, China Institute of Water Resources and Hydropower Research, Beijing 100048, China Kingland Technology Muhe Water-saving Equipment Company, Chifeng 024000, China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2017年第17期105-112,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家十二五科技支撑计划课题(2014BAD12B05)
关键词
灌溉
质地
含水率
地下滴灌
开沟播种
HYDRUS-2D
土壤有效饱和度
irrigation
texture
water content
subsurface drip irrigation
alternate row/bed planting
HYDRUS-2D
soil effective saturation
