不同水肥组合对高原夏季露地紫甘蓝产量和土壤理化性状的影响

为探究不同水肥条件对高原夏季露地紫甘蓝产量和土壤理化性状的影响效应,筛选适宜水肥管理制度,以当地灌水量和施肥量为对照(CK),设置3个灌水下限水平,即土壤相对含水量分别为田间持水量的80%(W1)、60%(W2)、40%(W3),3个施肥水平分别为当地常规施肥量的100%(F1:N、P、K分别为466.5 kg·hm~(-2)、756 kg·hm~(-2)、269.91 kg·hm~(-2))、80%(F2:N、P、K为373.2 kg·hm~(-2)、604.8 kg·hm~(-2)、215.93 kg·hm~(-2))、60%(F3:N、P、K为279.9 kg·hm~(-2)、453.6 kg·hm~(-2)、161.95 kg·hm~(-2)),共10个处理,分析紫甘蓝产量、土壤养分积累、pH、EC、土壤酶、土壤呼吸对不同水肥组合的响应规律。结果表明:(1)水肥一体化处理紫甘蓝单球重、经济产量、生物产量和经济系数均大于当地施肥灌水(CK)处理,其中,W2F2处理单球重、经济产量和经济系数较CK显著提高,分别提高了16.37%、16.37%、10.42%;(2)水肥一体化处理土壤蔗糖酶活性、过氧化氢酶活性和土壤呼吸强度均高于CK,其中,中水中肥(W2F2)处理较CK土壤有机质含量显著提升,增加26.76%;(3)在灌水下限相同时,随施肥量的增加,土壤蔗糖酶活性、过氧化氢酶活性和土壤呼吸强度表现为中肥(F2)处理高于高肥(F1)和低肥(F3)处理,土壤有机质含量表现为先升后降的趋势,在中水(W2)处理中F1、F2显著高于F3处理,而W1和W3各处理间并无显著差异;(4)施肥水平相同时,土壤蔗糖酶活性、过氧化氢酶活性和土壤呼吸强度表现为中水(W2)处理高于高水(W1)和低水(W3)处理。因此,60%田间持水量和N、P、K分别为373.2、604.8、215.93 kg·hm~(-2)的组合(W2F2)在节水减肥的基础上能最大程度提高产量和维持土壤理化性状,是高原夏季露地紫甘蓝适宜的灌水施肥组合。

Effects of different water and fertilizer combinations on yield of purple cabbage and soil physical and chemical properties on plateau in summer

In order to explore the effects of different water and fertilizer conditions on the yield of purple cabbage and soil physical and chemical properties in open field of plateau in summer, and screen the appropriate water and fertilizer management system, we took the local irrigation amount and fertilization amount as the control (CK), set three lower limit of irrigation volume of soil relative water contents at 80% (W1), 60% (W2), and 40% (W3) of the field water capacity, respectively, and three fertilization levels at 100% (F1: 466.5 kg·hm^-2 N, 756 kg·hm^-2 P and 269.91 kg·hm^-2 K), 80% (F2: 373.2 kg·hm^-2 N, 604.8 kg·hm^-2 P, and 215.93 kg·hm^-2 K) and 60% (F3: 279.9 kg·hm^-2 N, 453.6 kg·hm^-2 P, and 161.95 kg·hm^-2 K), a total of 10 treatments. The response of purple cabbage yield, soil nutrient accumulation, pH, EC, soil enzyme, and soil respiration to different combinations of water and fertilizer were analyzed. The results showed that: (1) the single ball weight, economic yield, biological yield, and economic coefficient of purple cabbage under the integrated water and fertilizer treatment were higher than those under the local fertilization and irrigation (CK) treatment, and the single ball weight, economic yield and economic coefficient of W2F2 treatment were significantly higher than those of CK, which increased by 16.37%, 16.37%, and 10.42%, respectively. (2) Soil sucrase activity, catalase activity, and soil respiration intensity of water and fertilizer integration treatment were higher than those of CK, among which, soil organic matter content of water and fertilizer (W2F2) treatment was significantly higher than that of CK by 26.76%. (3) At the same irrigation lower limit, soil sucrase activity, catalase activity, and soil respiration intensity were higher in medium fertilizer (F2) treatment than in high fertilizer (F1) and low fertilizer (F3) treatment, and soil organic matter content increased first and then decreased with the increase of fertilizer amount. In medium water (W2) treatment, F1 and F2 were significantly higher than that in F3 treatment, There was no significant difference between W1 and W3. (4) Under the same fertilization level, soil sucrase activity, catalase activity and soil respiration intensity were higher in W2 than in W1 and W3. Therefore, the combination of 60% field water capacity and 373.2 kg·hm^-2, 604.8 kg·hm^-2 and 215.93 kg·hm^-2 N, P, and K (W2F2) improved yield and maintain soil physical and chemical properties on the basis of water saving and weight loss, which was the optimum combination of irrigation and fertilization for purple cabbage in the region in summer.