CAJ | 학술논문

灌区地下水位调控可增加作物对浅层地下水的利用量，但当地下水含盐量较高时，作物对其利用会加快盐分在根区的累积速度，进而影响灌溉淋洗制度。本文根据农田水盐平衡的基本原理，考虑不同埋深的浅层地下水利用条件下根区土壤盐分的累积过程，建立了土壤盐分淋洗周期的理论模型，并根据两组试验数据进行了应用分析。计算结果显示，位于半干旱区的研究区，地下水含盐量4.43 g/L，埋深维持在1 m和1.5 m时，多年平均降雨条件下，棉花生长期内需要排水洗盐的周期分别为100 d 和140 d；埋深大于2 m 时，淋洗周期超过了生长期。另一研究区位于干旱区，滴灌棉田地下水埋深为1.5 m时，用含盐量为2.81 g/L的微咸水进行滴灌，棉花生长期内需要排水淋洗的时间为78 d左右。因此，即使在灌区水位调控抬高地下水位后，在一个生长周期内，根区土壤盐分的增长过程仍然相对缓慢，为灌区制定淋洗制度提供了时间窗口。
관구지하수위조공가증가작물대천층지하수적이용량，단당지하수함염량교고시，작물대기이용회가쾌염분재근구적루적속도，진이영향관개림세제도。본문근거농전수염평형적기본원리，고필불동매심적천층지하수이용조건하근구토양염분적루적과정，건립료토양염분림세주기적이론모형，병근거량조시험수거진행료응용분석。계산결과현시，위우반간한구적연구구，지하수함염량4.43 g/L，매심유지재1 m화1.5 m시，다년평균강우조건하，면화생장기내수요배수세염적주기분별위100 d 화140 d；매심대우2 m 시，림세주기초과료생장기。령일연구구위우간한구，적관면전지하수매심위1.5 m시，용함염량위2.81 g/L적미함수진행적관，면화생장기내수요배수림세적시간위78 d좌우。인차，즉사재관구수위조공태고지하수위후，재일개생장주기내，근구토양염분적증장과정잉연상대완만，위관구제정림세제도제공료시간창구。
Water table management in irrigated areas may increase shallow groundwater use by crops. But the high salt content of groundwater results in faster buildup of salinity in crop root zone,which in turn af-fects leaching schedule of the irrigation districts. Based on general salt and water balance in crop fields in irrigated areas, a simplified model was proposed in this paper to calculate leaching cycle for crops that use shallow groundwater at different water table depth, considering the salt accumulation process in root zone of crops. Subsequently, leaching cycles were calculated for two study sites with soil salinity measure-ments. For the case study in a semi-arid irrigation area,under the current irrigation scheduling and the av-erage rainfall condition, the calculated leaching cycle for cotton fields is 100 days for water table depth at 1 m and 140 days for water table depth at 1.5 m with the groundwater salinity maintained at 4.43 g/L;when the water table depth is greater than 2 m, the calculated leaching cycle is longer than the growing period. In another case study in an arid irrigation area with saline groundwater buried at 1.5 m deep, the calculated leaching cycle for plastic mulched and drip irrigated cotton is 78 days, applying slightly saline irrigation water with salinity of 2.81 g/L. These results indicate that managing water table depth under con-trolled drainage practice may increase crop use of shallow groundwater that contains dissolved salts, the rate of salinity buildup, however, is relatively slow, leaving a time window for making proper leaching schedule. The results from this study provide theoretical reference for salinity management in irrigated agri-cultural regions that adopt controlled drainage technique.