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ห้องสมุดกรมพัฒนาที่ดิน

Abstract
The study on the use of LDD soil test kit for recommendation of fertilizer
management for vegetables in in Lamphun province were conducted 2015 and
2016 at TeenDoi village, Ma Kok subdistrict, Pa Sang dictrict and Pun Ta Kern village,

Ton Tong subdistrict, Muang dictrict Lamphun province. The objectives of this study
were 1) to find out the suitable criteria for estimating of N, P and K application rates
from preplant soil analysis data for Chinese kale and Spring onion cultivation 2) to
compare soil analysis data analysed by soil analytical laboratory, and 3) to evaluate

the effectiveness of soil test kit for recommendation of chemical fertilizer application
rate for vegetables.
The experimented design for each vegetable was randomized complete
block design with 6 treatments and 4 replications. The treatments were as follows

1) control without chemical fertilizer application 2) chemical fertilizer application at
the farmer rate 3) chemical fertilizer application at the recommended rate of
Department of Agriculture (DOA) 4) application of N fertilizer by considering N

released from soil organic matter N uptake of the tested vegetable crop at the
expected yield and assuming that the tested crop having 50 % N fertilizer used
efficiency available P and exchangeable K and critical level of available P and
exchangeable K 5) N, P and K fertilizer application rates by considering N, P and K
uptake of the tested vegetable at the expected yield, soil analysis data of available P

and exchangeable K and adding more N, P and K fertilizers to compensate the lost
from leaching at 30 % of N, P and K uptake Tr.6) N, P and K fertilizer application rates
by considering soil analysis by LDD soil test kit and recommendation of DOA.

The experimental results indicated that there were no significant differences
of yields of Chinese kale and spring onion among treatment 2, 3, 4, 5 and 6 and
treatment 4 had the lowest cost of fertilizer input. It was found that the soil analysis
data obtained from LDD soil test kit was agreeable with those from soil analytical

laboratory and the differences of organic matter, available P and exchangeable K
between these two methods of soil analysis were not more than one level. When
the soil analysis data from soil test kit was used in combination on with the
recommendation of DOA for estimation of chemical fertilizer (Tr.6) for Chinese kale

and spring onion it was found that this fertilizer rate did not differ significantly from
treatment 2, 3, 4 and 5 for yield and this fertilizer rate could reduce cost of input on
fertilizer without yield declination. Furthermore the benefit per one unit cost of input
on fertilizer was higher than that from farmer rate. Thus, LDD soil test kit was