种植方式和灌溉定额对碱化盐土及紫穗槐生长的影响

针对甘肃白银碱化盐土表层土壤盐分高、植物生长困难的生产问题,在统一施用脱硫石膏18t/hm^2的基础上,通过2 a田间试验,在起垄沟植和未起垄种植2种种植方式下设置3个灌溉定额:8 250、9 750和11 250 m^3/hm^2,研究不同种植方式及灌溉定额对土壤pH值、碱化度、含盐量及紫穗槐生长的影响。试验结果表明:1)各处理均显著降低了土壤pH值、碱化度和含盐量;起垄沟植方式下垄沟内可汇集灌溉水和降水,提高土壤含水率;在0~40 cm土层起垄处理的土壤盐分比未起垄处理低15.7%,起垄沟植处理可以形成"高水低盐"的水盐环境,从而使紫穗槐的成活率、株高、冠幅均高于未起垄处理;2)2种种植方式下,随灌水量增加脱盐效果越显著,紫穗槐的成活率、株高、冠幅指标随灌水量增加而增加;灌溉定额为9 750和11 250 m^3/hm^2时,紫穗槐生长指标无显著差异。考虑到研究区地处干旱区,水资源有限,灌水量过多不仅浪费水资源还会增加发生次生盐渍化的风险,因此,施用脱硫石膏并起垄沟植适宜于甘肃白银碱化盐土紫穗槐种植,且适宜灌溉定额为9 750 m^3/hm^2。

Effects of planting patterns and irrigation quotas on alkalized solonchak and growth of amorpha

Saline-alkali soil is a general name referring to saline soil, alkaline earth salt and other saline and solonetzic soils. Accumulation of soluble salts in the proximity of the surface of saline-alkali soil could result in salt stress impeding crop growth as a result. Soil salinity is a limiting factor in agricultural production and an environment concern not only in China but worldwide. Gansu province in Chinahas a type of alkalized solonchak, a special saline soil characterized by high salt contentand poor soil structure which combined to impend crop growth. The purpose of this paper is to experimentally investigate the impact of planting patterns and irrigation amounts on soil salinity and plant growth in the alkalized solonchak. The experiment was conducted at Jingyuan in Gansu province (37°02'' N, 104°96'' E) using amorpha (Amorpha fruticosa L.) grown in the alkalized solonchak as the model plant. Prior to the experiment, desulfurized gypsum was applied to the soil at 18 t/hm2. We compared two planting pattern: furrow planting and non-furrow planting, and three irrigation amounts: 8 250, 9 750, 11 250 m3/hm2, each treatment having three replicas. The results show that: 1) All treatments significantly reduced soil pH, alkalinity and salt content, and there was no significant difference in pH and alkalinity between the treatments. Saltcontent in top 0-40cm soil under furrow planting decreased by 15.7% compared to that under non-furrow planting. 2) Under furrow planting, the irrigation and precipitation accumulated in the furrow ditch, thereby improving soil moisture and reducing soil salinity, compared thatunder non-furrow planting. Furrow planning improved survival rate, preservation rate, height, base diameter and crown width of the amorpha, compared to non-furrow planting. 3) There was no significant difference in growth index of the amorpha between the irrigation 9 750 and 11 250 m3/hm2, indicting excessive irrigation not only wasted water but also increased the risk of secondary salinization. Using raised-bed cultivation with the amorpha planted in the furrow, along with applying 18 t/hm2 of desulfurized gypsumand irrigating 9750 m3/hm2 of water was most suitable for improving plant growthin the alkalized solonchak in Gansu province. The results have wide application for developing sustainable agriculture inthe alkalized solonchakin Gansu and other regions.