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โครงการหนังสืออิเล็กทรอนิกส์ด้านการเกษตร เฉลิมพระเกียรติพระบาทสมเด็จพระเจ้าอยู่หัว

Abstract

The problem of farming and haze in the highlands is a repetitive problem, which is usually caused

by burning crop residues. Thus, four objectives are: 1) to evaluate landuse efficiency in maize/maize
seed planting, and integrated farming using crop yields evaluation, cost and return analysis, and

greenhouse gas (GHG) emissions from burning crop residues under current condition; 2) to evaluate
crop yields and nutrient losses (Nitrogen (N) and Phosphorus (P)) under climate change scenarios

employing EPIC model; 3) to estimate water runoff and sediment of each landuse patterns under
climate change scenarios; and 4) to investigate and analyze government policies implication

impacting on the farmers. The study area is Mae Chaem Watershed, Chiang Mai province. The target
group consists of farmers who grow maize/maize seed and integrated farming. Integrated farming in
this study refers to agricultural systems that have been planted over two or more species in the

same area. It is an economic crop. The important and popular growers in the Mae Chaem Watershed.
The EPIC (Environmental Policy Integrated Climate) model was used to assess the yield of

maize/maize seed and integrated farming and loss of nutrients (nitrogen and phosphorus) under
future climate scenarios. Cost-return and the emission of greenhouse gases from the combustion of

agricultural residual have been calculated and compared in each land use. Estimation of runoff and
sedimentation of each land use pattern under future climate scenarios have been evaluated by the

Soil and Water Assessment Tool (SWAT) under four scenarios namely maize/ maize seed (50%),
maize/ maize seed (0%), maize /maize seed (80%) and the perennial plantations (53.94%), forest

(28.56%) and other plants (17.7%).

The results of socio-economic in case of maize/maize seed and integrated farming found

that most of the agricultural land was outside irrigation. Households have a population between 2-
5 people and at most 6-8 people. Age range of the most common population is 31-50 years old.

Most of the population graduated from elementary school and is engaged in agriculture. Population
migrate is not much. The cost of the plant maize/maize seed and integrated farming include land

rental, soil management, water management, seed price, planting cost, fertilizer, weed control and
harvesting. The cost of maize cultivation was between 1,987-4,071 baht/rai and the average yield

was 876-2,083 kg/rai. Maize seed cost ranged between 1,071-3,520 baht/rai and average yield was
800-1,852 kg/rai. The integrated farming cost ranged between 5,084-30,564 baht/rai and the average
yield was 670-8,350 kg/rai. Comparing B/C ratio, the integrated farming was 2.04 which was more

cost effective than planting maize seeds (1.94) and maize (1.74), respectively.

Soil organic carbon density (SOCD) showed that SOCD was positively correlated with

elevation, clay content, soil moisture and Exchangeable Potassium. It was found that the yields of
maize/maize seeds were positively correlated with SOCD. In addition, the concentration of SOCD in

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