Effect of Negative Pressure Irrigation on Dry Matter Accumulation and Nutrient Absorption of Eggplant

Abstract

This article explores the effect of negative pressure irrigation on the dry matter accumulation and nutrient absorption of eggplants, which aims to screen out the most suitable soil moisture content for eggplant growth, and provide a reference for eggplant water management. In the greenhouse, this paper adopted a pot experiment, studied effects of negative pressure irrigation of three different water supply pressure, including −3, −8 and −15 kPa, and irrigation (CK) on the accumulation of dry matter, nitrogen, phosphorus and potassium nutrients of eggplant. The result showed that with the water pressure supply controlled in the range of −3 kPa to −15 kPa, the dry matter accumulation, nitrogen, phosphorus, and potassium nutrients of eggplant organs decreased, with the water supply pressure decreasing. With the pressure of water supply kept at −3 kPa in the late growth stage of eggplant, the dry matter accumulation of stem organ, fruit dry matter, and nutrients of nitrogen, phosphorus and potassium improved 17.42%, 8.06%, 30.37%, 36.93% and 23.65%, contrasted to the other irrigation treatments. There was a quadratic parabolic relationship between eggplant water consumption and yield and water use efficiency, and when the total water consumption was 59.57 L/plant, the yield reaches at a maximum that was 1479.86 g/plant, and water use efficiency reaches at a maximum that was 24.85 g/L. The negative pressure irrigation method is adopted in this article, and under the pressure of water supply maintained at −3 kPa, it is beneficial to the growth of eggplant, elevating the yield, nutrient absorption and irrigation efficiency, accomplishing the effects of water-saving.