Judul: Nutrient status of N and K in maize (Zea mays) intercropping system in The Land of Immature Oil Palm area
Abstrak: The increase in oil palm’s cultivation area is inversely proportional to the food crop’s area in Indonesia. Decrease in cultivation area for food crops should be a concern in order to provide sufficient food and additional food production for Indonesian community. Optimizing in immature oil palm plantation by applying intercrop system between oil palm and seasonal crops such as maize can be a way to increase food crop’s cultivation area while providing additional production and income in the mean time until the main crop (oil palm) become mature and ready to harvest. The aim of this research is not only analyzing N and K effect on maize’s growth and production but also analyze the effect of maize intercropping on palm oil growth. This research was carried out at Cikabayan Experimental Station, IPB University August - December 2020 using one factor randomized complete block design (RCBD). The treatment consists of four level fertilizer application, namely A0 (without treatment), A1 (240 g Urea + 80 g KCl + 320 g SP-36 per plot), A2 (480 g Urea + 160 g KCl + 320 g SP-36 per plot), A3 (720 g Urea + 240 g KCl + 320 g SP-36 per plot). Results showed that application of A3 (720 g Urea + 240 g KCl + 320 g SP-36) per plot significantly affect the number of leaves, plant height, cob’s lenght, stem diameter, plant weight, cob’s weight and husk free cob’s weight. Intercrop system of maize on immature palm oil plantation doesn’t affect oil palm’s growth.
Keyword: intercropping, maize, nutrient content, oil palm, intercropping, maize, nutrient content, oil palm

Judul: Optimasi Dosis Pupuk Majemuk NPK dan Kalsium pada Bibit Kelapa Sawit (Elaeis guineensis Jacq.) di Pembibitan Utama
Abstrak: Oil palm is the main estate crop that brought Indonesia as the main producer for palm oil in the world. Palm oil both crude palm oil (CPO) and kernel palm oil (KPO) have been broadening utilized by fractionation (edible oil), margarine, cosmetics, oleo-chemical and bio-diesel industries. The productivity of oil palm could be determined by the quality of seedling both genetically and physically. The production of oil palm seedling takes about 12-14 months through pre nursery (3-4 months) and main nursery (9-11 months). Fertilizer management had been necessary for oil palm seedling growth. Therefore, the accuracy fertilizer rate would be the main key to maintain the oil palm seedling growth physically as it would have produced the maximum growth of oil palm seedling. This research was aimed to evaluate rates of NPK compound and calcium fertilizer for the growth of oil palm seedling in main nursery. Other objectives were to know the interaction effect between NPK compound and calcium fertilizer and to produce the high qualified oil palm seedling. The experiment was conducted in IPB Experimental Station, Cikabayan, Darmaga, Bogor from December 2011 to November 2012. The two factor experiment was designed in a randomized block design with three replications. The rates of NPK compound fertilizer (15-15-15) were 0, 115, 230 and 460 g seedling-1. The rates of calcium fertilizer were 0, 5, 10 and 20 g seedling-1. In general, there was no interaction effect between NPK compound and calcium fertilizer on variables observed, except on plant height 3 Months after Application (MAA). NPK compound fertilizer had the significant quadratic effect on plant height, leaf number, stem diameter and chlorophyll content. But, it had the significant linear effect on plant height 5 MAA and stem diameter 3 MAA. The calcium fertilizer had the significant linear effect only on plant height 1 MAA and other variables were not affected by calcium fertilizer. The linear effect showed that the highest rate would still increase the seedling growth. The quadratic effect showed that the seedling growth would decrease by rate higher than the optimum rate. The oil palm seedling height of NPK compound rate 230 g seedling-1 on 8 MAA attained 85.48 % up to oil palm seedling standard for 12 months since pre nursery. Stem diameter and leaf number attained 106.92% and 65.56% respectively. Based on plant height and stem diameter, recommended rate of NPK compound fertilizer 15-15-15 was in the range of 333.00 g seedling-1 for eight months. Recommended rates for each month were 7.00, 7.00, 19.45, 59.25, 66.3, 61.55, 58.97 and 54.16 g NPK seedling-1. The optimum rate of calcium was not obtained from this experiment.
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Judul: Penyelesaian Masalah Pelabelan Graf vertex Magic pada Graf Cycle Sederhana
Abstrak: Graf vertex magic adalah suatu graf memiliki nilai bilangan magic yang sama pada masing-masing vertex yang berbeda. Graf cycle sederhana adalah suatu walk tertutup yang mengandung setidaknya tiga vertex, semua vertex-nya berbeda dan setiap vertex terhubungkan oleh satu edge.
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