秸秆带状覆盖下培土对马铃薯产量与水分利用效率的影响

Effects of earthing up on yield and water use efficiency of potato under straw strip mulching planting pattern

为了探明玉米秸秆带状覆盖下培土对西北雨养区马铃薯土壤水分及产量的影响,设置堆状培土(M1)、开沟壅土(M2)、沟播合土(M3)和不培土(CK)4个处理。通过2015-2016年大田试验,对比分析培土方式对生长指标、土壤含水率、产量及水分利用效率的影响。结果表明:偏旱年全生育期0~200cm土壤平均含水率均为M2最低。M3较CK显著提高了苗期0~60 cm土层土壤含水率,降低了块茎膨大期0~40 cm土层土壤含水率;M2较CK显著降低了块茎形成期40~60cm土层土壤含水率。平水年M1、M2、M3较CK显著降低马铃薯产量,但偏旱年M1、M2与CK差异不显著。偏旱年处理间水分利用效率差异不显著,但平水年CK分别显著较M1、M2、M3提高水分利用效率20.10%、24.89%、17.07%。在该试验条件下,秸秆带状覆盖种植马铃薯不需要培土。

Strip mulch of corn straw planting technique is a drought-resistant and moisture-preservation cultivation technique in the northwest rain-fed region of China. Previous studies mainly focused on the mechanism of increasing yield of this technology compared with plastic film mulching planting and conventional planting, while earthing up, a traditional cultivation method for potato in these retiongs, is not included. This study investigated the effects of earthing up patterns on soil moisture, yield and water use efficiency of potato under maize straw strip mulching in the northwest rain-fed Region of China. Four treatments included heap of earth-up(M1), furrow of earth-up(M2), trench planting and earth-up of filling furrow(M3) and no earthing up(CK). The field experiment was carried out in 2015 and 2016 at Tongwei Modern Dryland Circular Farming Experiment Station, Dingxi City, Gansu Province, China(35°11′N, 105°19′E, altitude 1 760 m). The year of 2015 was normal precipitation year and the year of 2016 was dry year compared with multiyear average. The No.7 of Longshu was planted. The plots with 3 replicates were designed by random arrangement method. Irrigation was not carried out during the experiments. The dry weight of straw, plant height, potato yield and its components were determined. The evapotranspiration was calculated based on water balance equation. The water use efficiency was the ratio of yield to evapotranspiration. In addition, soil moisture in different soil layers during the growing stages of potato was measured. The results showed that M1, M2 and M3 significantly reduced potato yields in normal precipitation year by 15.32%, 23.83% and 17.44%(P<0.05), respectively, compared with CK. Yield difference of among M1, M2 and CK was not significant in dry year, but M3 was significantly lower than CK by 7.85%. The difference of water use efficiency among M1, M2 and M3 was not significant in dry year, but CK significantly improved water use efficiency in normal precipitation year by 20.10%, 24.89% and 17.07%(P<0.05), respectively, compared with M1, M2 and M3. Based on the correlation analysis, the potato yield was highly correlated with yield and weight per potato, straw dry weight, biomass with the correlation coefficient of 0.83, 0.83 and 0.71, respectively. Thus, the yield of potato was mainly determined by weight per potato, straw dry weight, biomass. Compared to CK, M1、M2、M3 decreased weight per potato, biomass, straw yield and commodity potato rate, but increased height of plant and potato number per plant. In the whole growth period, the average soil moisture in 0-200 cm soil layers of the treatment of M2 was the lowest in the dry year however there was not different among treatments in normal precipitation year. Compared with CK, M3 significantly increased soil moisture content in 0-60 cm soil layer at seedling stage and decreased soil moisture content in 0-40 cm soil layer at tuber expansion stage. M2 significantly reduces the soil moisture content in 40-60 cm soil layer at tuber formation period. Maize straw strip mulching potato planting does not require earthing up under this experimental condition.