Study of Optimization Planting Patterns of Irrigation Areas Ciujung Ciruas District Using a Linear Program District Linear Program.

Study of Optimization Planting Patterns of Irrigation Areas a Abstract Ciujung Irrigation Area (DI) has an area of 21,350 ha. The Ciujung Irrigation Area Irrigation Network is still found to be quite high sedimentation, so that the distribution of water for agricultural needs and other community needs has not been able to be carried out optimally. The purpose of optimizing the planting pattern is to determine the maximum price of the crop that a field with different types of crops can produce. Optimization in this study used a linear program using the POM QM application. In this optimization study, 4 alternatives were planned with 2 different crops, namely corn and peanuts. In the planting pattern, alternative 1 starts planting in December I, alternative 2 starts planting in December II, alternative 3 starts planting in January I, alternative 4 starts planting in January II. The alternative planting pattern chosen is alternative 2 by producing an area of MT I Rice covering an area of 21,350 ha, MT II Rice covering an area of 3671.62 ha, Palawija covering an area of 84.98 ha and the maximum profit obtained in a year is IDR 595,113,300,000


Introduction
Ciujung Irrigation Area (DI) has an area of 21,350 Ha. The Ciujung Irrigation Area Irrigation Network is still found to have a fairly high sedimentation, so that the distribution of water for agricultural needs and other community needs cannot be carried out optimally [1]. It is necessary to conduct research and planning analysis. Optimization of irrigation water use is expected to meet the water needs of plants. In addition, it regulates a more optimal planting pattern based on the type of plant, land area and water availability [2] [3]. The objectives obtained from writing this final project are: A. To find out the irrigation water needs of the Ciujung Irrigation Area (DI). B. To find out the maximum profit from the production yield based on the planting pattern [4].

Literature Study 2.1 Planting Pattern
Planting pattern is an effort to plant on a piece of land by arranging the arrangement and order of plants in a certain period of time, both planting and non-planting periods. The

Hydrological Data
Hydrological data is needed to calculate irrigation water needs and mainstay discharge [11]. Hydrological data in the form of daily rainfall obtained from the Cidanau-Ciujung-Cidurian River Basin BBWS (Balai Besar Wilayah Sungai) [12].

Climatology Data
Climatology data can be used to calculate water requirements and irrigation water discharge including air temperature data, humidity data, duration of exposure to sunlight and wind speed. These data can be used to calculate evaporation and evaporation in plants.

Data Analysis and Discussion 4.1 Effective Rainfall Analysis (Re)
Hydrological data were obtained from the Cidanau-Ciujung-Cidurian BBWS (River Basin Center) in the form of monthly rainfall [13].  The annually aggregated monthly rainfall data is sorted from largest to smallest, then look for probabilities using the weibull formula [14]. Rainfall with a probability value of 80% is used to calculate effective rainfall in rice and rainfall with a probability value of 50% for palawija [15].

Analysis of Evapotranspiration Calculations (Eto)
Evaporation and transpiration events are simultaneously called evapotranspiration. The potential for evaporation is also commonly referred to as plant consumption needs, which is the amount of water needed to evaporate from the surface of the plant area. Climate plays an important role in determining these characteristics. Meteorological data include: temperature, humidity, wind speed and length of solar irradiation [16] The evaporation potential can be calculated using the Penman method Here is the calculation for Evapotranspiration

Analysis of River Discharge Calculation by FJ Method. Mock
Calculation of The Mainstay Discharge using the FJ method. Mock simulates river flow calculations using effective rainfall data, potential evapotranspiration and hydrological characteristics of watersheds [17].

Analysis of Farm Business Results
The results of the Farming Business are the result of a farmer's net profit from the harvesting process. Revenue is production minus production costs, which brings you a net profit [18]. The performance of agricultural production in each rice field is multiplied by the price of its products. The following is an analysis of the results of farming:

Planting Pattern Optimization
• Mathematical Model Optimization Based on the results of the analysis of water needs for each alternative and the mainstay denit so that it becomes an input for linear programs to obtain optimal planting pattern results.  Optimum land area results using the POM-QM for Windows 3 program generate data on the optimum surface area for each plant type for each alternative planting pattern and generate maximum profits based on agricultural analysis. The profit value is generated from the total area of each type of plant. In the table above, it can be seen that alternative 1 which has a maximum profit of Rp. 595,113,300,000 compared to other alternatives and the maximum irrigation water needs are 1.91 lt / dt / ha.

Conclusions
The conclusions that can be drawn from the results of the calculation and analysis of the study are as follows: 1. The amount of irrigation water needs for each alternative planting pattern is as follows: •