滴灌灌水量对枸杞土壤水分及养分迁移特征的影响

Effects of Drip Irrigation Amounts on Characteristics of Moisture and Nutrient Transfer in Soil in the Lycium barbarum Field

为探讨不同滴灌条件下枸杞园土壤水分及养分迁移的规律,采用田间试验研究了5个滴灌量水平(W 1为5100 m 3/hm 2,W 2为4350 m 3/hm 2,W 3为3600 m 3/hm 2,W 4为2850 m 3/hm 2,W 5为2100 m 3/hm 2)对枸杞土壤水分及养分迁移特征的影响。。结果表明:枸杞园土壤水分变化主要集中在20—60 cm土层,灌水后1~5 d,0—20 cm土层含水量随着灌水量的减少而增加,而20—40 cm及40—60 cm土层含水量为先减少后增加,当灌水量减少到一定程度时(低于2100 m 3/hm 2),各土层含水量下降。同时,不同处理土壤含水量随土层深度而逐渐增加。土壤养分迁移主要发生在0—40 cm土层,灌水后碱解氮向深层土壤的迁移量逐渐减小。灌水后不同处理有效磷在土壤剖面的分布趋势基本一致,主要富集在0—20 cm土层,其含量为90~200 mg/kg。土壤速效钾含量呈波动性变化,随枸杞生育期延长其含量逐渐降低。与常规滴灌量相比,W 4处理增加了土壤含水量,但W 2,W 5处理下土壤含水量降低,减缓了土壤速效养分向深层迁移,提高根层养分的吸收利用,有利于枸杞产量和品质的改善。可见,关键生育期调控灌溉可以作为调节土壤水分分布及土壤速效养分迁移转化的有效方式。

In order to investigate the characteristics of soil moisture and nutrient transfer under different irrigation amounts conditions in the Lycium barbarum field,a field experiment was conducted to study the effects of five drip irrigation amounts(W 1,5100 m 3/hm 2;W 2,4350 m 3/hm 2;W 3,3600 m 3/hm 2;W 4,2850 m 3/hm 2;W 5,2100 m 3/hm 2)on soil moisture and nutrient transfer in the Lycium barbarum field.The results showed that soil moisture changed dramatically in 20—60 cm soil depth in the Lycium barbarum field;soil moisture of 0—20 cm increased with the decrease of irrigation amounts,however,soil moisture decreased first and then increased in soil depth of 20—40 cm and 40—60 cm after drip irrigation from 1~5 d;the soil moisture in each soil depths began to decrease while the irrigation amount was reduced to a certain level(2100 m 3/hm 2);meanwhile,the soil moisture in different treatments gradually increased with the soil depth;transfer of soil available nutrients was mainly found in 0—40 cm soil depth,and soil alkali-hydrolyzed nitrogen leaching to the deep soil depth was less after drip irrigation;distribution of soil available phosphorus was very similar in the soil depth in different treatments after drip irrigation,and that was accumulated in soil of 0—20 cm with contents of 90~200 mg/kg;soil available potassium contents fluctuated,and that gradually decreased with the growing stages of Lycium barbarum;in contrast to conventional irrigation(W 1),soil moisture increased in treatment of W 4,but it decreased in treatments of W 2 and W 5,which retarded soil available nutrient leaching to deep soil depth,improved nutrient uptake and utilization in the root zone,and was beneficial to improve the yield and quality of Lycium barbarum.Therefore,regulating irrigation during key growth periods could be applied to regulate the distribution of soil water and the migration and transfer of soil available nutrients.