浅埋滴灌条件下灌溉定额对玉米根系形态特征和生理特性的影响

为研究浅埋滴灌条件下灌溉定额对玉米根系形态特征和生理特性的影响。以‘农华101’为供试品种,在浅埋滴灌条件下,灌溉定额设1600 m³/hm²(W1)、2000 m³/hm²(W2)和2400 m³/hm²(W3)3个处理,以传统畦灌灌溉定额4000 m³/hm²为对照(CK),于2017和2018年进行田间试验。结果表明,W1、W2处理与CK之间的玉米籽粒产量差异不显著,W3处理显著高于CK;各处理灌溉水利用效率均显著高于CK。玉米根干重,0~20 cm土层吐丝期2017年浅埋滴灌各处理均显著低于CK,2018年W1处理显著低于CK,W2、W3处理与CK之间的差异不显著,0~20 cm土层完熟期2年均表现为W1处理显著低于CK,W2、W3处理与CK之间的差异不显著;20~40 cm土层吐丝期和完熟期均表现为W1处理显著低于CK,W3、W2处理与CK之间的差异不显著。株、行间根幅10、20 cm土层处处理间差异不显著;30 cm土层处行间根幅W1、W2处理显著低于CK,W3处理与CK之间的差异不显著,株间根幅各处理均显著低于CK。根条数吐丝期10 cm土层处W3处理显著高于CK,W1、W2处理与CK之间的差异不显著,20 cm土层处W2、W3处理显著高于CK,W1处理与CK之间的差异不显著;乳熟期10、20 cm土层处均表现为W3处理显著高于CK,W1、W2处理与CK之间的差异不显著。根系活力各处理均低于CK,处理间随着灌溉定额的增加而增大,随着土层的加深差异逐渐减小;SOD、POD酶活性0~20 cm土层吐丝期和乳熟期处理间差异均不显著,20~40 cm土层吐丝期SOD、POD酶活性W1处理显著低于CK,W2、W3处理与CK之间的差异不显著,乳熟期SOD酶活性表现W1处理显著低于CK,W2、W3处理与CK之间的差异不显著,POD酶活性W1、W2处理显著低于CK,W3处理与CK之间的差异不显著;MDA含量0~20 cm土层吐丝期处理间差异不显著,乳熟期W1处理显著低于CK,W2、W3处理与CK之间的差异不显著,20~40 cm土层吐丝期和乳熟期处理间差异均不显著。浅埋滴灌节水灌溉使玉米根系在土壤表层分布比例增加,适当增加灌溉定额有利于提高玉米根条数和根系酶活性,可为水肥利用效率的提高创造条件。本研究可为玉米浅埋滴灌高产高效栽培提供依据。

Effects of Irrigation Quota on Morphological and Physiological Characteristics of Maize Root Under Shallow-buried Drip Irrigation

To study the effects of irrigation quota on the morphological and physiological characteristics of maize root under shallow-buried drip irrigation, field experiments were carried out by using ‘Nonghua 101’ as the experimental variety in 2017 and 2018. The irrigation quota of 1600 m³/hm² (W1), 2000 m³/hm² (W2) and 2400 m³/hm² (W3) were set under shallow-buried drip irrigation by taking 4000 m³/hm² irrigation quota of the traditional border irrigation as a control (CK). The results showed that there was no significant difference among the yield of W1, W2 and CK, and the yield of W3 was significantly higher than that of CK. The irrigation water use efficiency of each treatment was all significantly higher than that of CK. The root dry weight of each treatment under the shallow-buried drip irrigation in 0-20 cm soil layer were all significantly lower than that of CK in silking stage in 2017. The root dry weight of W1 was significantly lower than that of CK in 2018, while there was no significant difference among W2, W3 and CK. In the maturity stage in both 2017 and 2018, the root dry weight of W1 was significantly lower than that of CK, and the difference among W2, W3 and CK was not obvious. The root dry weight of W1 in 20-40 cm soil layer in silking stage and maturity stage were both lower than that of CK, and there was no significant difference among W3, W2 and CK. There was no significant difference among the root width between plants and rows of each treatment in 10 cm and 20 cm soil layer; the root width between rows of W1 and W2 were both significantly lower than that of CK in 30 cm soil layer, while W3 had no significant difference with CK, while the root width between plants of each treatment were all significantly lower than that of CK. In 10 cm soil layer, the root number of W3 was significantly higher than that of CK in silking stage, and there was no significant difference among W1, W2 and CK. In 20 cm soil layer, the root number per plant of W2 and W3 were significantly higher than that of CK, while W1 had no significant difference with CK. In 10 cm and 20 cm soil layer, the root number of W3 was significantly higher than that of CK in milk stage, and there was no significant difference among W1, W2 and CK. The root vitality of the treatments were all lower than that of CK, and the difference increased with the increase of irrigation quota while gradually decreased with the deepening of the soil layer. In 0-20 cm soil layer, the activities of superoxide dismutase (SOD) and peroxidase (POD) of each treatment had no significant difference in both the silking stage and milk stage. The activities of SOD and POD of W1 in 20-40 cm soil layer were lower than those of CK in silking stage, while there was no significant difference among W2, W3 and CK. The activity of SOD of W1 was significantly lower than that of CK in milk stage, while there was no significant difference among W2, W3 and CK, and the activity of POD of W1 and W2 were significantly lower than that of CK, and W3 had no significant difference with that of CK. The content of MDA of W1 was significantly lower than that of CK in 0-20cm soil layer in milk stage, and there was no significant difference among W2, W3 and CK. The content of MDA in 20-40 cm soil layer had no obvious difference among the treatments in both the silking stage and milk stage. The shallow-buried drip irrigation can increase the proportion of root distribution in topsoil, and appropriate increasing irrigation quota is conducive to the improvement of root number and root enzyme activity, which can increase water and fertilizer utilization efficiency. This article can provide a basis for maize high-yield and high-efficiency cultivation under the shallow-buried drip irrigation.