Evaluation of Intercropping System of Sweet Corn (Zea mays-saccharata Sturt) and Vegetable Soybean (Glycine max L. Merr) in Integrated Fertilizer Application

: The purpose of this study was to evaluate the intercropping system of sweet corn and vegetable soybeans on the application of combination different sources organic fertilizer and dosage of NPK fertilizer. The research was carried out from June to August 2022 in the Giwangan Umbulharjo village, Special Region of Yogyakarta. The study was arranged in a factorial Randomized Complete Block Design with three replication. The first factor were the source of organic fertilizer consisting of three sources (cow, chicken manure and municipal compost), the second factor were dosages of NPK consisting of three levels (200, 300 and 400) kg ha -1 , so that obtained 27 unit of experimental plots. The observation variable include component of growth, yield and efficiency land. The statistic analysis of data with analysis of variance (ANOVA) at a significant level of 5% followed by Duncan’s Multiple Range Test at a significant 5%. The result showed that the application of combination chicken manure with a dosages 300 kg ha -1 NPK fertilizer in the best growth and the highest yield of intercropping sweet corn and vegetable soybeans, and the component efficiency land showed the value of 1.55 Land Equivalent Ratio, 0.92 Competitive Index, 1.59 Crop System Efficiency and 1.07 Relative Yield Total.

organic soil in ponds of matter. In maize production systems, simply increasing the species richness cover crop will have little impact on agroecosystem services, but designing polycultures that maximize functional diversity can lead to multifunctional agroecosystem (Ku and Wa, 2017).
Based on the report by El-Negar and Mohamed (2019) that cow manure contains the mineral N. This process depends on the type of manure and its nutrient content, soil temperature, and humidity among other factors. Midransia et al. (2016) determinate that chicken manure in the most appropriate type of fertilizer to increases growth and production of sweet corn in shallow, lowland swamp areas. The chicken manure contains N (6.99 -7.78)%, P (0.89 -099)%, K Nitrogen (N) is an essential element that is required both in terms of in influencing plant productivity and negative environmental effects. The main source of N in organic systems can come from growing N-fixing legumes alternately with sweet corn> research on land application of combined manure with NPK and its effects on crop production is even rarer (Ahmed et al., 2020). Nitrogen fertilizers have been widely used to increase crop yield, but inadequate N inputs result in low yields and food shortages. In modern intensive agricultural production system, up to 50% of the N fertilizer applied to agriculture soil is lost to the environment (Zhao et al., 2022).
Intercropping system with legumes in a symbiotic manner can provide nitrogen nutrients that are able to potentially increase environmental resources and crop yields (El-Gobashy et al., 2018). Intercropping is beneficial in many ways as it ensures greater use of resources, reduced population of harmful biotic agents, higher resource conservation and soil health as well as more production and sustainable system outputs. In an intercropping system, more than one plant is planted together on the same soil and utilizes it's soil nutrients, soil moisture, atmosphere and sunlight. Intercropping has a strong potential to increase yields and thereby reduce global climate impacts such as greenhouse gases. Barriers to the locking effect for increased use of intercropping in organic farming and suggest a roadmap for innovation and strategy implementation in organic farming (Jensen et al., 2015). In the intercropping system, complementarity between the types of cultivated plant is very important to increase the yield of the two crops (Maitra et al., 2021). Several reports are available on cereal-based intercropping such as: corn-bean, corn-potato, corncassava, corn-yam, corn-soybean and corn-peanut, among many others and corn-peanut. Recent studies on intercropping have focused on cereal-vegetable mixtures (Samsuri et al., 2021). Based on the description above, it is hypothesis that the application municiple compost and a dosages 300 kg ha -1 NPK fertilizer can increase the yield and efficiency of intercropping sweet cornvegetable soybean.

MATERIAL AND METHODES
The research was carried out from June to Augustus 2022, in the Giwangan sub district Umbulharjo Yogyakarta. The research location is it an altitude of 115 meters above sea level, soil type gromusol, temperature (18 -16) o C, rainfall 200 cc monthly, high light intensity, humidity (50-90)% and soil pH 5.6 -6.6. Experiment Design, the field research was arranged in factorial Randomized Completely Block Design three replications. The first factor was the source of organic fertilizer namely chicken, cow manure and municipal compost at a dosage 20 tons ha -1. . the second factor was the dosage of NPK compound fertilizer, namely 200, 300 and 400 kg ha -1 . Control treatment with cow manure, urea, TSP and KCl fertilizers. The implementation of the research includes the making of experimental plots, soil preparation, basic fertilization with the application of organic fertilizer according to the dosage and source of organic fertilizer. Seed selection and planting with sweet corn spacing (75 x25) cm and vegetable soybean (25x25) cm, so that between two rows of sweet corn plant there are two rows of vegetable soybean. Embroidery was done one week after planting. Watering until the condition if it is not raining. Control of plant pest organism manually pest by picking, killing and burying and weeds by weeding/pulling and then buried. Observation of growth variables by destruction on plants ages 1 month, followed by generative growth until harvest. Variables observed for sweet corn and vegetable soybean include fresh weight and dry weight per plant, fresh weight of cobs and pods per plant, fresh weight of corn cobs and vegetable soybean pods ha -1 , chlorophyll contain, sweetness level of sweet corn seeds, Land Equivalent Ratio, Crop System Efficiency, Yield Relative Total and Competion Index. Data analysis used variance at a significance level of 5%, and continued with Duncan's Multiple Range Test at a significant level of 5%.

RESULTS AND DISCUSSION
The effect of types of organic and dosages of NPK fertilizers on plant growth. There was an interaction between sources of organic fertilizer and a dosage of NPK on plant dry weight and chlorophyll content, while other variables did not interaction, namely fresh weight of plant, sweet corn cob weight ha -1 , sweetness level and fresh weight of vegetable soybean pod ha -1 .        Dhonde et al. (2016) reported that the intercropping system of maize and long bean in arrow ratio of 2:2 increased the Land Equity Ratio to 1.15. The LER value is generally higher than indicating a higher yield advantage over monoculture. Likewise, Aswe and Maimela (2020) reported that intercropping the pathway system between cowpea and corn increased the yield, grain yield, LER and net yield. Not influenced by cropping pattern LER, ATER, A, CR were higher than sesame. In addition, planting cotton among sesame has higher monetary benefits than sesame monoculture (Donyavian et al., 2018). The highest seed yield was obtained in intercropping through 2 row of cowpea plants between maize plant. The land equivalent ratio is greater than for each intercropping (Nawar et al., 2020). Increasing the yield of long beans and corn in the intercropping system by giving a dosage of P fertilizer of 30 kg ha -1 and increasing the land equivalent ratio (Asiwe et al., 2021). The value of competition index show 0.92 the supported by Mekuanint (2017) that corn are more dominant than legume members.

CONCLUSION
Based on the description above, it can be concluded as follows: 1. There was an interaction between the source of organic fertilizer and the dosage of NPK fertilizer of 200-400 kg ha -1 on the dry weight of the plant and the chlorophyll content of the leaves of sweet corn, while other variables did not interaction. 2. The best growth of sweet corn intercropping with vegetable soybean was obtained from a combination of chicken manure or cow manure and 400 kg of NPK fertilizer. The growth of sweet corm plant with cow manure was not significantly different from municipal compost. 3. The highest yield of sweet corn cobs was obtained from the application of chicken manure, the lower yield was obtained from the application of cow manure and was not different from that of municipal compost.