基于香蕉根系分布特征的变量施肥机研制

针对香蕉施肥作业中肥量分布不合理和施肥效率低等问题,对香蕉根系的分布特征进行统计分析,获得基于根系分布特征的施肥决策,并以此为基础,设计了香蕉变量施肥机,进行了样机试验。结果表明:香蕉幼苗期的施肥长度≤0.22 m,主次施肥区的施肥量比例为8:5,施肥长度比例为2:1;营养体生长期的施肥长度≤0.42 m,主次施肥区施肥量比例为2:1,施肥长度比例为5:1;生殖体发育期的施肥长度≤0.84m,主次施肥区施肥量比例为11:5,施肥长度比例为3:1。田间试验结果表明,机具前进速度0.38m/s、排肥盘转速22r/min、漏肥孔圆心角120°时,排肥量理论值与实际值平均相对误差为5.74%,施肥合格率为93%,满足香蕉施肥作业要求;采用变量施肥机施肥的香蕉植株长势优于常规人工穴施肥。该研究为香蕉变量施肥机的研究提供了基础数据和设计新思路。

Development of variable rate fertilizer applicator based on distribution characteristics of banana roots

Fertilizer is an important condition for the crops growth and yield. In recent years, the use of agricultural fertilizer in China has increased significantly, which has brought a lot of environmental pollution and resource waste. Therefore, rational fertilization is one of the urgent problems in agricultural production. In order to solve the problems of unreasonable fertilizer distribution and low efficiency in banana fertilization operations by hands, this paper designed a variable rate fertilizer applicator based on the distribution characteristics of the banana roots. The distribution characteristics of banana roots at different growth stages were analyzed statistically, and the theory of variable rate fertilization was constructed. The fertilization decisions based on the distribution characteristics of banana roots were obtained, and the variable rate fertilizer applicator was designed, the prototype experiments were carried out. The results showed that the length of fertilization at the banana seedling stage was not more than 22 cm, the amount of total fertilization was not more than 0.150 kg, the ratio of fertilizer amount sowed in the primary and secondary fertilization areas was about 5:8:5 and the fertilization length ratio was about 1:2:1. The fertilization length at the vegetative growth stage was not more that 42 cm, the amount of total fertilization was not more that 0.200 kg, the ratio of fertilizer amount sowed in the primary and secondary fertilization areas was about 1:2:1 and the fertilization length ratio was about 1:5:1. The length of fertilization at the reproductive developmental stage was not more that 84 cm, the amount of total fertilization was not more that 0.300 kg, the ratio of fertilizer amount sowed in the primary and secondary fertilization areas was about 5:11:5 and the fertilization length ratio was about 1:3:1. The field tests results showed that when the forward speed of the fertilizer applicator was 0.38 m/s, the rotation speed of the fertilizer plate was 22 r/min, and the central angle of the leaking hole was 120°, the average relative error between the theoretical value and the actual value of the fertilization amount was 5.74%, the qualified rate of fertilizer application was 93%, which meet the requirements of banana fertilization operation. The growth of banana plants fertilized by variable rate fertilizer applicator was better than that of the conventional artificial drill fertilization.