Effects of phosphorus and potassium addition on growth and nod illation of Dalbergia sissoo in the nursery

摘要

A study was conducted to test the influence of different inorganic fertilizers (phosphorous and potassium) on the nodulation and growth of Dalbergia sissoo grown in the nursery. Before seeds sowing, different combinations of P, K. fertilizers were incorporated with the nutrient-deficient natural forest soils, and then amended with cowdung (soil: cowdung = 3:1). Nodulation status (nodule number, shape, fresh weight, dry weight and color) in the roots and the plant growth parameters (length of shoot and root, collar diameter, fresh and dry weight of shoot and root) were recorded 60 days after seeds sowing. Nodulation status and growth of the plants varied significantly (P ＜ 0.05) in the soils amended with fertilizers in comparison to the control. The highest nodule number (62), fresh (0.50 g) and dry (0.07 g) weights were recorded with the dose of PK at the rate of 160 kg/hm~2. Nodule shape and color also varied widely in different treatments. In case of plant growth parameters, shoot and root length, collar diameter, fresh and dry weight of the plants took on a significant difference (P ＜ 0.05) among various combination of fertilizers. From the study, it is revealed that PK at the rate of 160 kg/hm~2 fertilizer with soil and cowdung mixture (soil: cowdung = 3:1) is recommended for optimum growth and nodule formation of D. sissoo in degraded soils at a nursery level.%本文探测了无机肥(磷和钾)对苗圃内培养的印度黄檀生 长和结瘤的影响。播种前，磷和钾肥以不同比例混合后与营养 匮乏的自然林土壤混合，然后混合土再补以粪肥(混合土：粪 肥=3:1)。出苗后60天时记录植株结瘤状况(结瘤数、形状、 鲜重、干重和颜色)和植株生长参数(枝条和根长及鲜重和干 重、直径)。与对照相比，补充肥料的土壤显著地改变了植株 生长和结瘤状况(P ＜ 0.05)。植株结瘤的数目、鲜重和干重均 在磷钾施肥量为160kg／hm~2时达到最大值，分别为62，0.05g和 0.07g。不同比例的补肥处理改变了结瘤形状和颜色，同时显著 地影响了枝条和根长、直径、鲜重和干重等生长参数。研究揭 示：苗圃内生长的黄檀，在贫瘠的自然林土壤中施以160kg／hm~2 磷钾肥并混以粪肥(混合土：粪肥=3:1)可使植株生长和结 瘤的形成达最佳。