||Research on Mutual Effect of Root and Water in Ridge Culturing Pumpkin in Cold Highland Semiarid Region
||pumpkin,root system,water supply,soil root-growing space,yield,water use efficiency
1.盆栽试验条件下,模拟不同降水年型,设5个水分处理:贫水年型(W158,对照)、平水年型(W258)、丰水年型(W358)、贫补年型(W178,在小南瓜开花伸蔓期和果实膨大期补水,10mm/次)、平补年型(W278,在小南瓜开花伸蔓期和果实膨大期补水,10mm/次).结果表明:与对照相比,各供水处理的产量、干物质量及果实品质均有不同程度的提高.小南瓜的经济产量以W178和W278处理增加最高,分别为18 226.1kg·mm-1·hm-2和19 604.5kg·mm-1·hm-2,比W158处理增加了102.13%和117.41%.丰水年型(W358)虽供水较多,但产量低于W258、W178和W278处理.各供水处理小南瓜的果肉厚和单果重与对照相比增加的幅度分别为26.29%~42.25%和54.17%~116.67%.W278处理小南瓜的Vc和淀粉含量分别比对照显著提高31.25%和10.48%,蛋白质含量增加29.26%,果胶含量增加21.85%.小南瓜水分利用效率(WUE)以W178和W278处理最高,分别达89.57kg·mm-1·hm-2和64.76kg·mm-1·hm-2,分别比对照提高了91.55%和38.49%.W358处理的WUE低于对照.W258、W358和W278处理小南瓜的整根特征参数与对照相比均呈上升趋势,以W278处理根系的总根长、直径小于1mm的根长、总根表面积、总根体积最大,分别为对照的2.96倍、2.96倍、3.70倍、3.31倍,且根系干重最大,比对照增加50.05%.收获后小南瓜植株体内养分元素含量的变化为:全氮>全钾>全磷,叶片中全氮含量最高,叶柄中全钾含量最高.收获后土壤中速效P、K、有机质的含量与对照相比均降低.
2.根袋试验采用不同规格封底的尼龙袋(200目,允许水分和养分自由通过)装土,栽植小南瓜,限制根系生长的空间,以不套根袋(R0)为对照.结果表明:限根处理影响了小南瓜的生长,不同程度地降低了小南瓜的经济产量、干物质量、外观品质和水分利用效率.限根后,以R2处理(根袋口面积0.4m*0.4m,深0.3m)的产量最高,达11 902.9kg·hm-2;干物质量最大,达3 182.24kg·hm-2;外观品质最好,果肉厚度达2.80cm,单果重达1.42kg;水分利用效率最高,达56.56kg·mm-1·hm-2.限根后,不同处理小南瓜的营养品质以R3处理(根袋口面积0.5m*0.5m,深0.3m)效果最好,总糖含量达2.10%,淀粉含量达47.56%,果胶含量达9.14%.限根后,上层土体各处理的总根长和根系表面积均高于对照,增幅分别为19.60%~97.73%和26.41%~
||Sandy chestnut soil with drought, roughness and thin soil layer of field accounted for more than 65%of whole cultivated area in north-west of Hebei plateau. Uneven distribution of the rainfall in annual and internet-annual, which maked intra-regional agricultural production low and untable. Aparse planting pumpkin had the special resource utilization property. In the research, using sandy chestnut soil as the experimental soil and using pumpkin as the tested materials, potted experiment and root-bag control experiment were conducted, to study the response of different soil moisture and soil root-growing space to pumpkin and water efficient utilization of root under planting patterns with ridge culture and film mulching on furrow. The main results were as follows:1. Simulating different precipitation years through five water treatments: dry style(W158, CK), normal style (W258), wet style (W358), dry and make-up water style (W178, suppling water at flowering and vine elongation and fruit expanding process of pumpkins, 10mm/once), normal and make-up water style (W278, supplying water at flowering and vine elongation and fruit expanding process of pumpkins, 10mm/once) under the pot experiment condition.The results showed that: Comparing with control, the pumpkin''''s yield, dry matter quantity and fruit quality increased at different degree. The yield of W178 and W278 treatments reached 18 226.1kg·hm-2and 19 604.5kg·hm-2 respectively, which increased by 102.13%and 117.41%. The water supply quantity of wet style (W358) was more, but its yield was lower than W258, W178 and W278 treatments. The flesh thickness and average fruit weight increased by 26.29%~42.25%and 54.17%~116.67%compared with control. In comparison with control, Vc and starch content increased by 31.25%and 10.48%significantly, protein content increased by 29.26%, pectin content increased by 21.85%with the treatment of W278. In the treatment of W178 and W278, the water use efficiency (WUE) reached 89.57kg·mm-1·hm-2 and 64.76kg·mm-1·hm-2 respectively, which increased by 91.55%and 38.49%.The WUE of W358 treatment was lower than control. Characteristic parameters for the whole roots of W258, W358 and W278 treatments showed increasing trend compared with control. In W278 treatment, the total root length, root length less than 1mm, the total surface area and the total volume were the largest, which were 2.96times, 2.96times, 3.70times and 3.31times than that of control, respectively. The root dry weight increased by 50.05%compared with control. The change of nutrient content of plant for post-harvest showed that: total nitrogentotal potassium total phosphorus, the content of total nitrogen was the highest in leaves and the content of total potassium was the highest in petiole.The content of available N, P, K and organic matter for post-harvest were lower than d control.2.Comparing with non-bagged (R0), soil culture was conducted with the pumpkin planted in bottom sealing nylon bags of different specifications to confine the space of root growth but allow the pass-through of water and nutrients, the confinement of root growth space decreased the yield, dry matter quantity, fruit quality and water use efficiency. After root restriction culturing, the yield was largest which attained 11 902.9kg·hm-2; dry matter quantity reached 3 182.24kg·hm-2; flesh thickness was 2.80cm, average fruit weight reached 1.42kg; water use efficiency was the highest which reached 56.56kg·mm-1·hm-2 with the treatment of R2 (the port area of root-bag is 0.4m*0.4m, depth is 0.3m). The content of total sugar reached 2.10%, the content of starch reached 47.56%, the content of pectin reached 9.14%, with the treatment of R3 (port area of root-bag is 0.5m*0.5m, depth is 0.3m) which flesh quality was the best effect. The total root length and surface area were higher than control, which increased by 19.60%~97.73%, and 26.41%~96.33%; the total root volume and root length less than 1 mm were lower than control, which increased by 38.12%~54.34%and 81.21%~86.29%in upper soil layer; the total root length, root length less than 1mm, the total surface area and the total volume increased than the control; which were9.04times~23.48times,5.96times~7.83times,11.07times~24.53times,9.76times~15.67 times compared with control, respectively, in lower soil layer after the confinement of root growth space. Root dry weight increased than the control, which increased by 17.01%~77.13%; above-ground dry weight decreased by 37.04%~64.77%; root-shoot ratio decreased by 37.04%~64.77%except treatment R1. The change of nutrient content of plant for post-harvest showed that: total nitrogentotal potassium total phosphorus, the content of total nitrogen was the highest in leaves and the content of total potassium was the highest in petiole.