Amending Soil with Absorbent Polymers to Avert Banana Yield Decline after Reducing Chemical Fertilizations

Abstract

【Objective】 Excessive fertilization is often used by farmers as an insurance in crop production. It not only wastes resources but also risks environmental pollution and soil degradation. Reducing agrochemical fertilization has hence been mandated in China in developing sustainable agriculture. The purpose of this paper is to investigate the efficacy of amending soil with a water adsorbent to avert banana yield reduction after reducing chemical fertilization. 【Method】 The experiment was conducted at an acidic soil in Hainan province; it consisted of three treatments: ①conventional fertilization by applying 596.8 kg/hm2 of N, 312.8 kg/hm2 of P2O5 and 1 850.3 kg/hm2 of K2O (CK); ②reducing 55% of N and P2O5 respectively, and 50% of K2O (T1); ③reducing 55% of N and P2O5 respectively, and 50% of K2O combined with soil amendment with 219.2 kg/hm2 of a water-absorbing polymer (T2). 【Result】 Compared with CK, amending the soil with the adsorbent increased girth and leaf numbers of the plant (P<0.05); it also increased the yield by 18.3% to 54 242 kg/hm2, in addition to the 144.7% increase in partial factor productivity. The net income of after the soil amendment was 61 700 yuan/hm2, 137.4% higher than that of the CK. Its output-input ratio increased from 1.22∶1 in the CK to 1.58∶1. 【Conclusion】 Top-dressing 268.6 kg/hm2 of N, 140.5 kg/hm2 of P2O5 and 925.2 kg/hm2 of K2O, coupled with amending the soil with 219.2 kg/hm2 of absorbent polymer annually, not only improved fruit yield after reducing the fertilization but also improved fruit yield and boosted the income of farmers.

Keywords

• reducing chemical fertilization
• drip irrigation
• banana
• water absorbent polymer
• fruit yield