Effects of content of controlled release nitrogen and potassium on banana yield and NPK fertilizer use efficiency | 控释氮钾比例对香蕉产量及氮磷钾肥料利用率的影响

Chinese. 研究控释配方肥中控释氮钾比例对香蕉产量和养分吸收利用的影响，确定适宜的控释养分比例，为香蕉专用控释配方肥的研制及其在香蕉上的应用提供科学依据。采用大田试验，将控释氮钾比例设置5个水平(0%，15%, 30%, 45%, 60%)，以不施肥为对照，研究控释氮钾养分比例高低对香蕉产量和养分吸收的影响。与常规肥料处理(控释氮钾比例均为0%)相比，控释氮钾配方肥能协调产量构成要素而显著提高香蕉产量，其中以控释氮钾比例均为45%处理的产量和产值最高，分别为33.95 t/hm2和4.64万元/hm2，增产率和增值率分别为38.00%和41.46%，这主要是由于该处理明显增加了果指长、果指数、单果质量及收获率等产量主要构成因子。控释氮钾比例从0%增加到60%时，产量、产值以及氮磷钾养分吸收利用均呈现先增加后降低的趋势。当控释氮钾比例为45%时，氮、磷、钾肥料表观利用率最高，分别达41.24%，5.37%和64.97%，较常规肥料处理分别增加了21.48，2.98和29.44个百分点。在0%～45%，提高控释氮钾的比例，可促进香蕉对氮磷钾养分的吸收利用，提高氮磷钾肥料的利用率，增加香蕉产量和产值，适宜的控释氮钾比例为45%左右。

English. Effects of content of controlled nitrogen and potassium in bulk mixed with controlled release fertilizers (BBCRF) on banana yield, NPK absorption and fertilizer use efficiency were investigated to determine the optimal proportion of controlled nitrogen and potassium in BBCRF and promote the development and application of controlled release fertilizers in banana cultivation. The research included 5 treatment groups with different proportions of controlled nitrogen and potassium (0%, 15%, 30%, 45%, and 60%), and 1 control group without fertilizer. Field experiments were conducted to research the effects of the ratios of controlled nitrogen and potassium on banana yield and NPK uptake efficiency. Compared with the control group, the banana yield and yield component factors of BBCRF treatment groups increased significantly. The maximum yield (33.95 t/hm2) and output value (46 400 yuan/hm2) of banana fruit were observed in the treatment using BBCRF with 45% of both controlled N and K2O. The banana yield and output value increased by 38.00% and 41.16%, respectively. What increased the yield and output value in this treatment was the fact that BBCRF promoted finger length, number of fingers, weight of single finger and harvest rate. When contents of controlled release N and K2O increased from 0% to 60%, both banana yield and output value increased initially, reached peak values when the ratios of controlled release N and K2O were at 45%, and then decreased with the increase of the ratio. The highest N, P2O5, and K2O use efficiencies (41.24%, 5.37%, and 64.97%, separately) were found in the treatment of BBCRF with 45% of both controlled N and K2O. The N, P2O5, and K2O use efficiencies increased by 21.48, 2.98 and 29.44 percentage points, respectively. NPK fertilizer use efficiency, yield and output value of banana can be improved by increasing proportion of the controlled release N and K2O in total nutrients from 0% to 45%, and the optimum ratios of both controlled release N and K2O are 45%.