The performance of Arabica coffee (Coffea arabica L.) depends on the climate, soil, pests, and elevation. Information on the performance of Arabica coffee growing in the changing climate of North Sumatra has not been available so far. To provide such information, 28 genotypes were studied. The nested design used three factors. Seven climate zones, two locations in each climate zone, and two coffee farms (genotype, G) in each location were selected. The research showed that the genotypes were highly significantly different (α = 0.01). G5, G6, and G20 produced the heaviest hundred beans. G13, G19, and G25 suffered the least coffee berry borer infestation (CBBI). The length of rainy season became the most important factor (r2 = 0.54). The CBBI (y, %) correlated significantly and negatively with the elevation (x, m) with the equation of y = 46.4 – 0.025x. The climate zones showed a significant difference (α = 0.05). The genotypes produced heavy beans also in two wet months of the rainy season and one dry month. The temperature (x, °C) was the most important factor affecting CBBI (r2 = 0.65) with the equation of y = –338.2 + 15.5x. The soil pH correlated significantly and positively with beans weight and bean width.

Research took place in University of HKBP Nommensen, Faculty of Agriculture Research Greenhouse in Simalingkar, Medan, Indonesia. Hypothesized that the application of manure as a singgle factor could increasing the soil water holding capcity and soil cation exchange capacity.Research designed with Complete Randomize Design,the treatment replicated by four times.Every parameter that effected significantly will be continued analized with Duncan's Multiple Range Test. For observation had made by measures of soil water holding capcity and soil cation exchange capacity.The concluding of the research can be explain thatThe Effects of manure application on sandy soil after 30 days of incubation at rate of application equal with 20 t/ha has significantly increased soil water holding capacity only at 72 hours after saturation. The Effects of manure application on sandy soil after 15 as well as 30 days of incubation at all rate of application has not significantly effected cation exchange capacity. Keys words: manure, water holding capacity, and cation exchange capacity ABSTRAK Penelitian akan dilakukan di Rumah kaca Fakultas Pertanian Universitas HKBP Nommensen Medan, di Desa Simalingkar B. Dalam penelitian ini diduga bahwa aplikasi pupuk kandang terhadap tanah berpasir dapat memperbaiki kapasitas pegang air dan kapasitas tukar kation tanah. Inkubasi dilakukan selama 30 hari ( 6 September 2014 -6 Oktober 2014 ). Rancangan percobaan yang digunakan dalam percobaan ini adalah Rancangan Acak Lengkap (RAL). Pupuk kandang (K)diberikan 6 taraf aplikasi dengan 4 kali ulangan. Untuk mengetahui bagaimana pengaruh perlakuan terhadap kapasitas pegang air tanah dilakukan pengujian kadar air tanahpada15 dan 30 hari setelah inkubasi dan untuk mengetahui bagaimana pengaruh perlakuan terhadap KTK tanah dilakukan dua kali pengujian KTK tanah, yaitu pada 15 hari dan 30 hari setelah inkubasi. Setiap prlakuan yang berbeda nyata dilanjutkan dengan uji jarak berganda Duncan. Dari hasil penelitian dapat disimpulkan bahwa:aplikasi pupukkandang setara 20 ton/ha setelah inkubasi selama 30 hari pada tanah berpasir dapat meningkatkan kapasitas pegang air tanah 72 jam setelah penjenuhan, sedangkan pemberian baik dibawah maupun diatasnya hingga setara dengan 50 ton/ha dan waktu inkubasi 15 hari maupun 30 hari tidak berpengaruh nyata terhadap perbaikan kapasitas tukar kation tanah.Kata kunci: pupukkandang, kapasitas pegang air, dan kapasitas tukar kation PENDAHULUAN Sebagai media tumbuh bagi tanaman, tanah merupakan sumberdaya alam yang utama untuk menunjang usaha pertanian yang menjadi andalan dalam mempertahankan keberlanjutan pemenuhan kebutuhan pangan, sandang dan papan bagi manusia di biosfer ini. Kerusakan tanah yang kita kenal sebagai

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