尿素与磷酸二氢钾配施对板栗光合特性及生长结实的影响

肥料配施可提高肥料利用效率,改善树体营养结构,起到平衡施肥的作用.选取7年生板栗树为试材,采用树干注射的方法,研究尿素和磷酸二氢钾不同配施处理对板栗光合特性及生长结实的影响.结果表明: 尿素和磷酸二氢钾配施具有明显的正向协同效应,二者配施较单一施肥可显著提高板栗光合能力及产量和品质.单施(NH₂)₂CO可降低叶绿素含量,单施KH₂PO₄可增加叶绿素含量,而二者配施使叶绿素含量显著增加.4种配施处理均可提高叶片及枝条的N、P、K含量,其中0.3%(NH₂)₂CO+0.3%KH₂PO₄处理效果最好.不同施肥处理均可改善光合参数,但仍以配施处理为好,其中0.3%(NH₂)₂CO+0.3%KH₂PO₄处理可显著提高光合速率、最大净光合、表观量子效率、羧化效率、瞬时水分利用效率、氮素利用效率.配施可同时促进枝条加长和加粗生长,并提高混合芽数量,而单施(NH₂)₂CO仅能促进加长生长,对提高混合芽数量效果不显著.配施对提高坚果产量和质量效果优于单一施肥,在0.3%(NH₂)₂CO+0.3%KH₂PO₄处理下坚果产量、单粒质量和总糖含量等关键指标较对照分别提高68.2%、25.5%和14.9%.

Effects of compound fertilizer of (NH2)2 CO and KH2PO4 on the chestnut photosynthesis characteristics,growth and fruiting.

Compound fertilizer can improve the fertilizer use efficiency and tree nutrition status to ensure balanced fertilization. Taking 7 year-old chestnut trees as test material, with (NH₂)₂CO and KH₂PO₄ being mixed at the different ratios, the effects of different compound fertilizers on the photosynthesis characteristics as well as the growth and fruiting of chestnut were studied quantitatively by trunk injection method. Results showed that compound fertilizer of (NH₂)₂CO and KH₂PO₄ induced positive synergistic effects to enhance photosynthetic capacity, yield and quality of chestnut obviously. The content of chlorophyll was decreased by (NH₂)₂CO and increased by KH₂PO₄, but increased obviously by the compound fertilizer. The contents of N, P, K of leaf and branch rose under the four compounded fertilization treatments, among which 0.3%(NH₂)₂CO+0.3%KH₂ PO₄ was the best. All fertilizer treatments could advance the photosynthetic parameters, while the compound fertilizer performed better. 0.3%(NH₂)₂CO+0.3%KH₂PO₄ treatment significantly increased the photosynthetic rate, the maximum net photosynthesis, apparent quantum yield, carboxylation efficiency, instantaneous water use efficiency and nitrogen use efficiency. Compound fertilizer could promote the growth of branch in diameter and length synchronously, and increase the number of mixed buds, while (NH₂)₂CO only promoted the growth of branch in length, and did little in the number of mixed buds. The compound fertilizer did better in advancing nuts yield and quality than single fertilization of N or P. The nuts yield, mass and total sugar were increased by 68.2%, 25.5% and 14.9% respectively under 0.3%(NH₂)₂CO+0.3%KH₂PO₄ treatment compared with the control.