The Effects of Irrigation and Fertigation on Yield, Water-fertilizer Utilization of Pepper in Hainan Province

Abstract

【Background and objective】 Hainan province is a pepper base in China and its traditional production uses furrow fertigation, resulting in not only water and fertilizer waste but also nutrient leaching and contaminating the environment. The purpose of this paper is to explore suitable irrigation and fertilization methods to improve water and fertilizer use efficiency without compromising pepper yield. 【Method】 The experiment was conducted in field plots with four different irrigation - fertilization combinations: furrow irrigation without fertilization (CK), furrow irrigation with fertilization of 470.70 kg/hm2 of N + 511.22 kg/hm2 of P2O5 + 526.39 kg/hm2 of K2O (F1), furrow irrigation with fertilization of 376.55 kg/hm2 of N + 314.83 kg/hm2 of P2O5 + 526.39 kg/hm2 of K2O (F2), mulched micro-spray with fertilization of 376.55 kg/hm2 of N + 314.83 kg/hm2 of P2O5 + 526.39 kg/hm2 of K2O. In each treatment, we measured yield and fruit quality, photosynthesis, root growth, nutrient accumulation and nutrient distribution in soil, as well as water and fertilizer use efficiency. 【Result】 When N and P were initially high in the soil, F1 and F2 did not show significant difference in their yield, fruit quality, root growth, photosynthesis and accumulation of N, P and K in the plant. In contrast, F3 increased the yield, transpiration, root length, root surface area, root volume, accumulation of N, P and K by 8.03%, 16.91%, 60.69%, 43.00%, 40.37%, 19.30%, 14.19% and 14.61%, respectively, compared to F2; it also showed significant differences in fruit quality, net photosynthetic rate, stomatal conductance and intercellular CO2 concentration from F2. Compared with F1, F2 reduced the contents of total N, ammonium N, total P and available P in the 0~20 cm and 20~40 cm of soil after the harvest, reduced the apparent surplus N and P, and improved the partial productivity of N and P fertilizers. Compared with F2, F3 increased the contents of total N, nitrate N, ammonium N, total P and available P in the 0~20 cm of soil, reduced the apparent surplus N and P, and improved the production rate of the irrigation water. 【Conclusion】 For all treatments we compared, mulched micro-spray irrigation with reduced fertilization (F3) improved yield, water and fertilizer use efficiency of the pepper.

Keywords

• pepper
• irrigation and fertilization
• fruit yield
• soil nutrient
• water and fertilizer utilization