两茬收割饲用甜高粱灌溉定额试验研究

为探索饲用甜高粱最佳灌溉定额和节水效果,设置了不同灌溉定额(2 400, 3 000, 3 600, 4 200, 4 800 m³/hm²)对两茬收割饲用甜高粱生长和生物产量的影响的田间试验.结果表明,甜高粱茎粗和株高的峰值分别出现在播后62 d和158 d.随灌溉定额增加甜高粱在形态上表现为株高增加、茎粗减小的趋势.在头茬收割(播后76 d)时,株高日增长率最大,为4.00~4.89 cm/d.两茬收割甜高粱鲜生物学产量为63.9~115.5 t/hm²,干生物学产量为12.7~21.4 t/hm²,全生育期耗水量为326.95~504.24 mm,鲜生物学产量WUE为15.53~24.63 kg/m³,干生物学产量WUE为3.89~4.51 kg/m³.灌溉定额为4 200 m³/hm²时,甜高粱总鲜、干生物量最大,灌溉定额为4 800 m³/hm²时,甜高粱总鲜、干生物量增幅不大.从节水和增加生物量角度而言,畦灌方式下的两茬收割饲用甜高粱全生育期灌水4次,灌水定额为1 050 m³/hm²,灌溉定额为4 200 m³/hm²的灌溉效果最佳.

Experimental study on irrigation quota of two crops harvesting feeding sweet sorghum

In order to explore the optimal irrigation quota and water-saving effect suitable for feeding sweet sorghum, a field experiments was conducted to study the effect of the irrigation quota(2 400, 3 000, 3 600, 4 200, 4 800 m³/hm²respectively)on growth and biomass of two crops of feeding sweet sorghum. Results showed that the peak of stems diameter and plant height of sweet sorghum appeared respectively at 62^th days and 158^th d after sowing. Plant height increased with increasing irrigation quota, while stems diameter had a reducing with increasing irrigation quota. Daily growth rate of sweet sorghum appeared at 76^th days after sowing was the biggest, which were between 4.00-4.89 cm/d. With different irrigation quota, fresh or dry biomass of sweet sorghum was 63.9-115.5 t/hm² and 12.7-21.4 t/hm² respectively, water consumption of that in the whole growth stage was 326.95-504.24 mm, WUE of fresh and dry biomass was 15.53-24.63 kg/m³ and 3.89-4.51 kg/m³ respectively. When irrigation quota was 4 200 m³/hm², Fresh or dry biomass of two crops of sweet sorghum were all the biggest, and no significant increase was achieved by adding irrigation quota. In conclusion, for water-saving and increasing the biomass, irrigation schedule with irrigation quota of 4 200 m³/hm²(irrigation frequency was 4 times)was thereby recommended as an optimized irrigation to increase the biomass of two crops of feeding sweet sorghum.