Growth and Yield of Upland Rice Under Intercropping System with Soybean in Sandy Coastal Area Fajrin Pramana Putra*, Prapto Yudono, and Sriyanto Waluyo Department of Agronomy, Faculty of Agriculture, Universitas Gadjah Mada Jln. Flora no. 1, Bulaksumur, Sleman, Yogyakarta 55281, Indonesia Corresponding email: fajrin.pramana.p@gmail.com Received: 23 rd May 2017; Revised: 22 nd August 2017; Accepted: 29 th December 2017 INTRODUCTION Rice is one of the essential food crops for the people of Indonesia. One of the types of rice cultivated in Indonesia is upland rice. Upland rice is cultivated on dry land that is not watered throughout its lifetime and water source comes from soil moisture derived from rainfall (Sumarno and Hidayat, 2007). The contribution of upland rice production is still 5% of the total rice production in Indonesia (Kementan, 2016). The role of upland rice to provide food and national grain supply is going to become important in the future. This is due to the decreasing of wetland and the indication of the rice production rate does not increase, while the increase of population rate continues to increase at an average rate of 1.17% per year (BPS, 2016). National issues about low grain productions can be solved by cultivating upland rice in the sandy coastal area. Indonesia has a long coastline of 106.000 km and the land area of 1.060.000 ha, generally including marginal land (Saparso et al. , 2009). Sandy coastal area has a potential for the development of food crops such as upland rice. Sandy coastal area is supported by soil water availability that is relatively shallow and abundant sunshine (Wibowo, 2006). However, the sandy coastal area is marginal land that has limiting factors such as the ability to save water which is low, high infiltration, organic matter and soil fertility are very low (Al-Omran et al ., 2004). Management of sandy coastal area can be done with the soil enhancers material in the form of clay and manure (Rajiman et al., 2008). To solve the low fertility of the sandy land can be done by planting soybeans between upland rice or intercropping system. Intercropped with soybean can provide many benefits Ilmu Pertanian (Agricultural Science) Vol. 2 No. 3 December, 2017 :130–136 Available online at http://journal.ugm.ac.id/jip DOI: doi.org/10.22146/ipas.25215 ISSN 0126-4214 (print) ISSN 2527-7162 (online) ABSTRACT Sandy coastal area in Indonesia is potential for upland rice cultivation, but it has constraints low of nutrient availability such as nitrogen. To solve the low fertility of the sandy land can be done by planting soybean between upland rice under intercropping system due to the soybean is able to provide nitrogen in soil through fixation of N2 in the air by root nodules. Intercropping is an alternative cropping system to increase land productivity, but there is competition between crops under an intercropping system. Reducing of the competition on the system is needed by crops proportion adjustment. The objective of the study is to examine growth and yield component of upland rice at different crops proportion under an intercropping system with soybean in the sandy coastal area. The research was conducted in Samas sandy coastal area, Bantul, Yogyakarta. This research used randomized complete block design (RCBD) with one factor and three blocks. The treatment of this research was five level crops proportion between upland rice and soybean under intercropping system, namely: 100:0; 80:20; 60:40; 40:60; and 20:80, respectively. The results showed that crop growth rate and yield per clump of upland rice increased on crops proportion adjustment under intercropping system with soybean. The crops proportion of 60:40 and 40:60 gave higher crop growth rates that were 1.45 g.dm -2 .wk -1 and 1.44 1.45 g.dm -2 .wk -1 than upland rice under monoculture (100:0) that was 1.09 g.dm -2 .wk -1 . The higher crop growth rates in crops proportion of 60:40 and 40:60 were able to give better yield per clump than other that were 17.17 g and 16.46 g, respectively. The yield of upland rice was not different under crops proportion of 100:0, 80:20, and 60:40 and decreased of upland rice proportion until ≤ 40% affected the low yield of upland rice. Keyword: Crop growth rate, crops proportion, intercropping, yield