Modelling Growth and Yield of Aerated Pepper by the Logistic Model

Abstract

【Objective】 Aeration is to supply oxygen to the root zone by bubbling the irrigation water. It is an effective irrigation technology to improve crop growth in heavy-textured soils with low air permeability. The aim of this paper is to experimentally study the effect of aeration on growth and yield of pepper. 【Method】 The experiment was conducted in a greenhouse designed using a three-factor randomized block. It consisted of two nitrogen applications: 225 kg/hm2 (N1) and 300 kg/hm2 (N2), two aerations with the volumetric fraction of the air being 0% (C) and 15% (A) respectively, and two irrigation amounts: 682.8 m3/hm2 (W1) and 1 024.2 m3/hm2 (W2). Crop growth traits in each treatment, including plant height, dry matter and yield, were described by the logistic model. 【Result】 Second day after irrigation, the water-filled soil pore space (WFPS) increased significantly (P9.0% (P0.980 (P<0.01). Aeration increased both maximum elongation rate and the average elongation rate over the rapid growth period of the crop by 13.0% and 11.8%, respectively, compared to the control without aeration. Similar as nitrogen application and irrigation, aeration also increased above-ground dry matter and fruit yield significantly (P<0.05). Of all treatments, fertilizing 300 kg/hm2 of N, irrigating 1 024.2 m3/hm2 of water, and adding 15% of air bubbles to the irrigation water achieved the highest yield, 324.63 g/plant. Fruit yield was positively correlated with oxygen diffusion rate and plant height. 【Conclusion】 Aerated irrigation can significantly improve soil aeration, promote crop growth and accumulation of dry matter, thereby increasing fruit yield. The logistic model describes the elongation of the crop well regardless of the treatments.

Keywords

• pepper
• aeration irrigation
• logistic model
• growth characteristics
• yield