Pengaruh Kelas Kemiringan dan Posisi Lereng terhadap Ketebalan Lapisan Olah, Kandungan Bahan Organik, Al dan Fe pada Alfisol di Desa Gunungsari Kabupaten Tasikmalaya

Abstrak

ABSTRACT

Effect of slope gradient and its position to plow depth layer, organic matter, Al and Fe contents

This research was done to know the influence of slope gradient and its position to plow depth layer, organic matter, Al and Fe contents. This research was carried out January-March 2011. The research used survey method with descriptive comparative analysis with free physiographic approach based on land cover. Sampling technique was used a purposive stratified sampling. Soil sampel took from three slope gradients: 8-15%, 16-25% and 26-40% with three position of crest, middle and lower positions. The result showed that the gradient of slope and its position have influenced plow layer depth and content of iron but organic material and Al were not influenced. The highest of plow layer depth and content of iron were occured at 8-15%, while the highest of content of Al and iron were occured at 16-25 %. Based on slope position, the thick of plow layer, the content of organic matter, Fe were
occured highest in the lower position and Al was occured in the middle position.

Keywords: Slope, plow depth layer, organic matter, Al, Fe

ABSTRAK

Penelitian ini dilakukan untuk mengetahui adanya pengaruh dari kelas kemiringan dan posisi lereng terhadap ketebalan lapisan olah, bahan organik, Al dan Fe. Penelitian dilakukan pada bulan Januari-Maret 2011 dengan menggunakan metode survai dan analisis deskriptif komparatif melalui pendekatan fisiografis secara bebas berdasarkan penampakan fisiografis lahan. Teknik sampling berdasarkan metode sampel pertimbangan dalam stratifikasi. Contoh tanah diambil dari tiga kelas kemiringan lereng : 8-15%, 16-25% dan 26-40% dengan tiga posisi lereng yaitu posisi atas, posisi tengah dan posisi bawah. Hasil penelitian menunjukkan bahwa kemiringan dan posisi lereng berpengaruh terhadap ketebalan lapisan olah dan kandungan Fe sedangkan terhadap bahan organik dan kandungan Al tidak berpengaruh. Ketebalan lapisan olah dan bahan organik tertinggi dijumpai pada kemiringan lereng 8-15% sedangkan kandungan Al dan Fe tertinggi yaitu pada kemiringan lereng 16-25%. Berdasarkan posisi lerengnya, ketebalan lapisan olah, bahan organik, kandungan Fe tertinggi dijumpai pada posisi lereng bawah sedangkan kandungan Al pada posisi lereng tengah.

Kata Kunci: Lereng, Ketebalan lapisan olah, Bahan organik, Al, Fe