基于作物耗水特性的夹砂地膜下滴灌模式优选

Optimal Mode Selection of Mulched Drip Irrigation in Sand Layered Field Based on Water Consumption Characteristics

在2个灌水水平下(I1:高水,I2:低水)以不同滴灌带间距(A1:1 m,A2:0.5 m)与覆膜方式(M1:全膜覆盖,M2:半膜覆盖)进行2 a田间试验,结合作物产量、作物水分利用效率(WUE)以及产投比筛选适宜的膜下滴灌模式,并利用产量水分敏感系数(ky)确定最优的膜下滴灌模式。结果表明:在低频灌溉模式下,部分覆膜处理的蒸腾(ET)高于全覆膜处理,而产量和WUE低于全覆膜处理。尽管滴灌带间距对ET的影响不明显,然而在高水处理下,"一管单行"作物的产量与WUE高于"一管双行"。高频灌溉模式下,作物产量及WUE对灌溉量、覆膜方式、滴灌带间距的响应呈现耦合性。低频灌溉条件下,ky对灌溉量及滴灌带间距的响应均不显著,而部分覆盖处理WUE低,ky高,对水分胁迫的响应敏感。高频灌溉条件下,覆膜方式、灌溉量以及滴灌带间距均对ky产生影响。高频灌溉条件下,ky能对经WUE筛选出的膜下滴灌处理进行进一步的优选。基于ky的结果,结合产量、水分利用效率与产投比,建议在高频灌溉条件下采取"全膜低水+一管双行"模式或"半膜高水+一管单行"模式,在低频灌溉条件下采取全膜高水模式。

Judgement of crop water requirement just by soil water content is not competent, which is closely related with crop yields and water use efficiency. Corn water consumption and yield in response to mulching method （MI： fully mulched and M2： partially mulched）, and irrigation amounts （I1 and I2） under variable drip irrigation lateral spacings （AI： 1 m and A2： 0. 5 m） were investigated over two growing seasons in the Hetao Irrigation District under arid growing conditions. Results showed that evapotranspiration （ET） in partially mulched treatments were higher than that in treatments with full mulch cover under low irrigation frequency. However, the yields and water use efficiency （WUE） were lower under partial mulched treatments compared with full mulch. Closer lateral spacing had no effect on ET under low irrigation frequency, but yield was increased with high irrigation amount under low irrigation frequency. The yield response factor （ky） of the crop water production function （CWPF） was sensitive to mulching method and it was lower in partially mulched treatments than in fully mulched treatments under low irrigation frequency. Under high irrigation frequency, ky was sensitive to irrigation amounts, mulching methods and lateral spacing. The CWPF along with WUE and crop yield can aid in the selection of optimal irrigation and mulching management. Considering k.. yield. WUE and costs partial mulch with 1 m lateral spacing under high irrigation amount and full mulch with 0.5 m lateral spacing with low irrigation amount was optimal under high irrigation frequency while either 1 m or 0.5 m lateral spacing under partial mulch with low irrigation amount was optimal under low irrigation frequency, respectively. This study can guide irrigation application for maize in the Hetao Irrigation District.