Growth and Phosphorous Absorption Rate of Red Pepper as Affected by Top Dressing Applications of Phosphorus Fertilizer in Different Cropping System

Abstract

An experiment was conducted to study the effect of top dressing application of Phosphorus (P) fertilizer on the growth and P absorption rate of red pepper in different cropping systems of the upland. P fertilizer was applied with no treatment as control (CON), basal dressing application (BDA), 2 times-split of top dressing applications (2-TDA) and 3 times-split of top dressing applications (3-TDA). Red peppers were grown for 110 days and soil characteristics and crop growth were investigated every 20 days. Dry matter yield of red pepper significantly increased at the 2-TDA and 3-TDA but decreased at the CON and BDA due probably to the decrease or increase in available P. In particular, at 3-TDA there was an increase in growth and P absorption rate of red pepper. The fruit dry matter weight of red pepper receiving 3-TDA was 961.7 kg 10a-1, which was significantly higher than those receiving CON and BDA in Rainproof cultivation. In case of the Rainproof cultivation, we found out both P fertilization use effect and top dressing applications effect because there was low available P content of soil used in the experiment in comparison other cultivation type. Therefore, considering the dual goal of optimum crop growth and maximum P distribution instead of immobilization with soil, this study suggests that a testing of a site-specific proper application method of P including top dressing applications is prerequisite to achieving optimum agricultural productivity while minimizing nutrition quality misuse. Uptake of P by red pepper plants after 110 days of cultivation. Cultivation type Treatment P uptake 110DATᚋ (kg 10a-1) Protected cultivation CONᚌ 1.19ab† BDA 1.01b 2-TDA 1.14ab 3-TDA 1.51a Rainproof cultivation CONᚍ 0.82b BDA 1.18b 2-TDA 1.36b 3-TDA 1.91a Open field cultivation CONᚎ 0.77b BDA 1.08a 2-TDA 0.60bc 3-TDA 0.55c 110DATᚋ means day after red pepper plants cultivation CONᚌ: no fertilization as control, BDA: aplication with P at 1.3 kg 10a-1, 2-TDA: aplication with P at 0.65, 0.33, 0.33 kg 10a-1, 3-TDA: aplication with P at 0.65, 0.22, 0.22, 0.22 kg 10a-1 in Protected cultivation CONᚍ: no fertilization as control, BDA: aplication with P at 3.7 kg 10a-1, 2-TDA: aplication with P at 1.85, 0.93, 0.93 kg 10a-1, 3-TDA: aplication with P at 1.85, 0.62, 0.62, 0.62 kg 10a-1 in Rainproof cultivation CONᚎ: no fertilization as control, BDA: aplication with P at 3.8 kg 10a-1, 2-TDA: aplication with P at 1.9, 0.95, 0.95 kg 10a-1, 3-TDA: aplication with P at 1.9, 0.63, 0.63, 0.63 kg 10a-1 in Open field cultivation †Mean values(n=3), with different lowercase letters indicating significant difference at p=0.05 by Duncan's multiple range test.