COMBINATION OF PLANTING METHODS AND MULTIPLE NPK FERTILIZER ON PLANT GROWTH AND PRODUCTION

This study aims to obtain differences in the response of growth and yield of Sweet Corn (Zea mays saccarhata Sturt) using a single row planting system and a two row planting system. This research was conducted in Sukajadi Village, Banyuasin Regency, South Sumatra Province. Research time in January. This study used a split plot design with 8 treatment combinations which were repeated 4 times. The treatment factors in question are as follows: Main Plot : Single Row Planting System (S1), Two Row Planting System (S2), P0: No treatment , P1: NPK : 60g (plot) P2: NPK : 120g (plot) P3 : NPK : 180g (plot). The variables observed in this study were plant height/plant (cm), length of seed cob/plant (cm), cob weight/plant (gr), production of plots/plot (kg). Based on the results of the study, it was shown that the treatment with a two-row planting system (DB) and application of 300kg/ha compound NPK fertilizer gave the best effect on sweet corn production of 12.96 kg/plot or equivalent to 17.28 tons/ha.


INTRODUCTION
Sweet corn is one of the most popular vegetable commodities in America, Canada and Asia, one of which is Indonesia. In Indonesia, sweet corn has been known since the 1980s [1]. Corn production centers are spread across various regions in Indonesia such as Central Java, East Java and Madura, then it is widely planted outside Java [2].
One way to improve cultivation techniques is to adjust the planting system. The use of the right cropping system can be an important factor to get high yields, because the cropping system determines the number and population of plants per unit area [3].
The setting of the planting system is related to the spacing used. If the spacing is too wide, it is less efficient in land use, if it is too narrow, there will be high competition and result in low productivity. The regulation of plant population density and spacing of cultivated plants is intended to suppress competition between plants [4].
According to the research results of [5], stated that the single row cropping system resulted in the best growth and production with the best average plant height of 215.65 cm and cob weight of 642 g/cob and without husks, respectively, and 574.5g/cob.
In addition to regulating the cropping system, one of the efforts that can be made to increase sweet corn production can be done by providing or adding nutrients, namely through fertilization.
There are two types of fertilizers, namely organic fertilizers and organic fertilizers. To accelerate the absorption of nutrients in plants, organic (chemical) fertilizers can be given.
Pearl NPK fertilizer is also known as compound fertilizer because it contains more than 2 types of main nutrients, with nutrient content of N (15%) in the form of NH3, P (15%) in the form of P2O5 and K (15%) in the form of (K2O) . Phosphorus (P) plays an important role in energy transfer in plant cells, promotes root development and early fertilization, strengthens stems so that they do not fall easily, and increases N uptake at the beginning of growth. The element potassium (K) also plays a very important role in plant growth, for example to stimulate the translocation of carbohydrates from leaves to plant organs [6]. [7] argues that the recommended dose of compound NPK fertilizer for sweet corn is 150 kg/ha, with a yield of 13 tons/ha.

Place and time of research
The research was carried out in Sukajadi Village KM 15, Talang Kelapa District, Banyuasin Regency, South Sumatra Province. The time of the study was carried out from November to January 2020.

Materials and Tools
The materials used in this study were sweet corn of Master sweet variety, compound NPK fertilizer, chicken manure, dolomite, and fungicides. Meanwhile, the tools used in this study were hoe, machete, waring, hose, water pump, meter, rafiah rope, wooden tug, stenlis knife, nameplate, gembor, and scales.

Research Design
This study used a split-plot design with 8 treatment combinations which were repeated 4 times with a total of 32 plots. The treatment factors in question are as follows: Factor I: Planting System (S), with 2 types of planting system, namely: S1: 1 row planting system and S2: Two row planting system.  The numbers followed by the same letter in the same column mean that they are not significantly different at the 95% confidence level. Table 1a shows that the P 3 treatment was significantly different from the other treatments and produced the highest plant height of 203.08 cm.      Note: The numbers followed by the same letter in the same column mean that they are not significantly different at the 95% confidence level Table 3b shows that the S2P3 interaction treatment was not significantly different from the S1P2, S1P1 and S2P2 treatments, but was significantly different from the other treatments and produced the highest cob weight per plant, which was 370.75 g.

Cob Weight Each Plot (kg)
The results of the analysis of the  Table 4.