生物质炭施用量对旱作娃娃菜光合及水肥利用效率的影响

Effects of Biochar Dosage on Photosynthesis and Water and Fertilizer Use Efficiency of Baby Vegetables in Dryland

旨在确定出适合宁南山区旱作娃娃菜的最佳秸秆生物质炭添加量,为宁南山区雨养菜地土壤培肥和蔬菜安全生产提供理论依据。从2020年开始,以娃娃菜为参试作物,采用随机区组试验设计,连续2年采用大田试验,以不施任何肥料和生物质炭为完全空白对照CK,研究不同生物质炭施用量(0、10、20、30 t·hm^(-2))与氮肥配施对旱作娃娃菜生长、光合、产量和品质、水肥利用效率及土壤理化性质、土壤酶活性的影响。结果表明:施用生物质炭与否对于根系无显著影响,但对于旱作娃娃菜而言,生育期的降水量会影响整个娃娃菜的生长和产量;添加生物质炭处理净光合速率累计值高于不添加生物质炭处理;添加30 t·hm^(-2)生物质炭并陈化一年可显著提高蔗糖酶、碱性磷酸酶、脲酶活性分别在2.12%、1.19%、13.68%以上,提高产量8.11%以上,节水9.84%以上,增收4316.85元·hm^(-2)以上。因此,综合考量品质指标、生产成本、经济效益、水肥利用效率及生物质炭的陈化效应,确定出配施氮肥条件下,添加30 t·hm^(-2)生物质炭为宁南山区雨养旱作娃娃菜的最佳秸秆生物质炭添加量,一定程度上可实现节水增产增效,同时得出生物质炭添加量越大,陈化对其效果发挥影响越小。

The aim of this study was to determine the optimal amount of straw biochar added to the dry-farming baby cabbage in the mountainous area of southern Ningxia,and to provide a theoretical basis for soil fertilization and safe production of vegetables in the rain-fed vegetable fields in the mountainous area of southern Ningxia.Starting from 2020,by using the baby cabbage as the tested crop,the randomized block experiment design was adopted,and the field experiments were conducted for two consecutive years with no fertilizer and biochar as a complete blank contrast(CK),in order to study different biochar application rates(0 t·hm^(-2),10 t·hm^(-2),20 t·hm^(-2),and 30 t·hm^(-2))combined with the application of nitrogen fertilizer on the growth,photosynthesis,yield and quality,water and fertilizer utilization efficiency,soil physicochemical properties and soil enzyme activities of the dry-farming baby cabbage.The results showed that:the application of biochar or not had no significant effect on the root system,but the amount of precipitation during the growth period could affect the growth and yield of the whole baby cabbage in dry farming.The cumulative value of net photosynthetic rate in the treatment of adding biochar was higher than that without adding biochar.The addition of 30 t·hm^(-2) biochar and aging for one year could significantly increase the activities of sucrase,alkaline phosphatase and urease by more than 2.12%,1.19%and 13.68%,respectively,increase the yield by more than 8.11%,save water by more than 9.84%,and increase the income by more than 4316.85 yuan·hm^(-2).Therefore,comprehensively considering the quality index,production cost,economic benefit,water and fertilizer utilization efficiency and the aging effect of biochar,it was determined that under the condition of combined application of nitrogen fertilizer,the addition of 30 t·hm^(-2) biochar was the optimum addition amount of straw biochar for the rain-fed dry-farming baby cabbage in the mountainous area of southern Ningxia,which could achieve water saving and yield&efficiency increasing to a certain extent.At the same time,it was concluded that the greater the addition amount of biochar,the smaller the effect of aging on it was.