Optimization of Planting Patterns Based on Water Availability and Needs for Agriculture (Case Study of Pecangaan Irrigation Area, Jepara Regency)

Optimization of Planting Patterns Based on Water Availability and Needs for Agriculture (Case Study of Pecangaan Irrigation Area, Jepara Regency) Paper in ........, Correction........, Accepted ....... EXTENDED ABSTRACT The current condition of water resources in Indonesia is faced with the availability of water which tends to decrease to have water needs in various sectors. Agriculture is an important sector in economic development, considering its function and role in food security for the community. Success in managing water resources for agriculture is influenced by water availability and irrigation management on agricultural land. Irrigation planning and management based on climatology and hydrological data is needed to estimate the amount of water availability and water requirements on agricultural land. However, the current condition of water resources is faced with water availability which tends to decrease and less distribution resulting in limited irrigation water to agricultural land. As the result, agricultural productivity is not optimal. Therefore an effective and efficient management of water resources is needed in order to have water needs for agriculture. The current problem faced especially in Jepara Regency is the area of agricultural land that cannot be irrigated properly and evenly, especially in the dry season. With the limited water availability, in agricultural land, it is necessary to find alternatives and optimize cropping patterns in accordance with existing conditions. The location chosen to conduct this research is in Pecangaan Irrigation Area which irrigates 702 ha of agricultural land. The purpose of this study is to calculate the availability of water, determine alternative planting patterns and determine the optimum planting patterns based on water availability and water needs, case study in the Pecangaan Irrigation Area. This research is useful to find out the area of land and types of plants that will be planted to get the maximum benefit by setting cropping patterns during the third planting season. This research is also expected to be a reference for other locations that have similar criteria. The research method in the study begins with collecting climatology data and characteristics of agricultural plants. Then the climatology data analysis is done using New LocClim software. While the analysis to calculate crop irrigation water requirements is used Cropwat 8.0 software. Furthermore, for the optimization analysis with the linear program method using the solver function on Microsoft Excel. The results showed that the availability of water in Planting Period (MT) was 4,117,347 m3; MT 2 of 9,067,275 m3 and MT3 of 2,072,276 m3. Water requirements for irrigation with existing cropping patterns (paddy- paddy-paddy/maize/fallow) namely at MT1: 2,496,948 m3; MT2: 2,481,340 m3; MT3: 2,071,284 m3. Planting area in MT 1 is 702 ha (paddy), MT 2 is 702 ha (paddy) and MT 3 is 133 ha, where MT3 consists of 131 ha paddy and 2 ha maize. Income of farmers with existing conditions, namely in MT1: Rp 9,022,806,000; MT2: Rp 9,022,806,000 and MT3: Rp 1,702,063,000. Optimization of cropping patterns is done to maximize the income of farmers in the Third Planting Season (MT3) with various alternatives of several types of plants based on the availability of water available. Alternative planting patterns are carried out for the third planting season (MT3) with crops suitable for MT3, and farmers in Pecangaan Irrigation area have planted these crops because they are related to farmers' habits and skills and are suitable to the soil and climate conditions in the land. In addition, the periode of the plant starts to plant until the harvest is not more than 4 months in accordance with MT3. If the period of the plant is more than 4 months, it will disrupt the cropping pattern in MT1. Types of plants as an alternative to MT3 besides paddy namely maize, sweet potato, peanuts, green beans, melons and watermelons. Based on the selection of these plant types a combination of 10 alternative cropping patterns is arranged. The optimization of cropping patterns in MT3 has alternatives 1 to alternative 10. It can be concluded that alternative planting patterns 4 (paddy- melons) provide maximum income of Rp 4,640,906,339 with irrigation water needs of 1,354,951 m3, with a 10 ha rice planting area and 420 ha melons. Then the results of the optimization of alternative 1 (rice - corn) with a cropping pattern of paddy (10 ha) and maize (447 ha) earned an income of Rp 4,226,712,229. While the condition of the existing cropping patterns in MT3 with the paddy planting pattern (131 ha) and maize (2 ha) earned an income of Rp 1,702,063,000. If compared, the income of farmers in alternative planting patterns 4 will increase by Rp 2,938,843,339  from the existing cropping patterns. Thus the planting index (IP) in MT3 increase from 18.94% to 61.25%.