Studies on Proper Doses of Fertilize for Cassava planting in Loamy Soil : Huai Pong Series

Abstract

To increase cassava production in present situation of costly chemical fertilizer,
perform good nutrient management which is specified to production area should be
determined. Therefore, the response of cassava to nutrient management in loamy soil in
eastern part of Thailand had been investigated. This research was aimed to get the most
effectively recommendation of fertilizer application for cassava grown in loamy soil. The
experiment was conducted on Huai Pong Soil Series (Hp) loamy soil, at Muang District,
Rayong Province during 2011 to 2013. The experimental design was a split-plot with three
replications. Main plot consisted of three cassava varieties: Rayong 9, Rayong 11 and
CMR46-47-137. Sub-plot was implemented with ten procedures of fertilizer application:
0-0-0, 16-8-16, 16-8-0, 0-8-16, 16-0-16, 16-8-8, 8-8-16, 24-8-16, 16-8-24 and 16-16-16 kg
(N-P2O5-K2O)/rai. Results showed that variety and fertilizer were significantly affected to
cassava yield. Rayong 9 gave the highest yield at 6,274 fresh weight kg/rai and 1,990 starch kg/rai followed by CMR46-47-137 provided 5,982 fresh weight kg/rai and 1,791 starch kg/rai.
While, Rayong 11 gave the lowest yield at 5,941 fresh weight kg/rai and 1,777 starch
kg/rai. Using fertilizer of 16-8-24 kg (N-P2O5-K2O)/rai gave the most benefit and
net income (13,586 baht/rai), suited for economic return. All three cassava varieties showed potassium uptake higher than nitrogen and phosphorus uptake. Rayong 11 showed the highest nitrogen and potassium uptake. Cassava production at yield 6,065 kg/rai was required 2.72,
5.56 and 17.07 of N-P-K (kg/rai) uptake or input fertilizer at 2.72, 12.73 and 20.48 of
N-P2O5-K2O (kg/rai).