Penekanan aluminium tanah akibat pemberian bahan organik pada tanah jenis podsolik.

anglais. One of the major restriction of acid-racing podzolic is the high soil interchangeable aluminum (Al-dd) content. The addition of any organic materials (OM) such as cattle faeces can not only increase soil C-organic content but also reduce soil interchangeable aluminum and increase soil pH. The purpose of this research was to find out the extent of influence of adding organic materials, i.e., cattle faeces, on both the reduction of soil Al-dd and increase of podzolic-type soil pH. The research was carried out in Soil Fertility Laboratory of Agricultural Faculty, Padjadjaran University. The model used was a one-factor random model, that is the dosage of organic materials (O) with four levels, i.e., with or without control (00), 2.5 mega gram OM per ha (O1), 5.0 mega gram OM per ha (O2), and 7.5 mega gram OM per ha (O3). Each of which was repeated 6 times. The amount of experimental units = 4x6 = 24 units. Then, the soils were kept in a 80 percent field capacity condition and incubated for one month. In the end of period of incubation, an analysis of soil on both Al-dd variable and pH of soil. Based on the results, it was found out that the addition of organic materials considerable reduced soil Al-dd and increase soil pH. Every one mega gram organic material added to soil resulted in a reduction of 0,161 me 100 g soil Al-dd and increased 0,082 pH unit of soil pH. The addition of organic materials has a direct influence on the change of soil Al-dd. In turn, the change on the soil Al-dd influence the change of soil pH.

Salah satu kendala utama dari Podsolik bereaksi masam adalah kandungan aluminium dapat dipertukarkan (Al-dd) tanah yang tinggi. Pemberian bahan organik seperti kotoran sapi selain dapat meningkatkan kandungan C-organik tanah, juga dapat menurunkan kandungan aluminium dapat dipertukarkan tanah dan meningkatkan pH tanah. Penelitian ini bertujuan untuk mengetahui berapa besar pengaruh pemberian bahan organik (BO) berupa kotoran sapi terhadap penurunan Al-dd tanah dan peningkatan pH tanah jenis podsolik. Penelitian ini dilaksanakan di Laboratorium Kesuburan Tanah Fakultas Pertanian Universitas Padjadjaran. Rancangan yang digunakan adalah Rancangan Acak Lengkap satu faktor yaitu dosis bahan organik (O) dengan empat taraf yaitu: tanpa atau kontrol (O0), 2,5 mega gram BO per hektar (O1), 5,0 mega gram BO per hektar (O2), dan 7,5 mega gram BO per hektar (O3). Masing-masing diulang sebanyak 6 kali. Jumlah unit percobaan = 4x6 = 24 unit. Selanjutnya tanah dipertahankan dalam kondisi 80 persen kapasitas lapang dan diinkubasi selama 1 bulan. Akhir masa inkubasi dilakukan analisis tanah terhadap variabel Al-dd tanah dan pH tanah. Beberapa hasil penelitian diketahui bahwa pemberian bahan organik sangat nyata menurunkan Al-dd tanah dan meningkatkan pH tanah. Setiap mega gram bahan organik yang diberikan ke tanah menyebabkan Al-dd tanah menurun sebesar 0,161 me 100/me 100 per g meningkatkan pH tanah sebesar 0,082 satuan pH. Pemberian bahan organik berpengaruh secara langsung terhadap pertumbuhan Al-dd tanah. Perubahan yang terjadi terhadap Al-dd tanah tersebut mempengaruhi terhadap perubahan pH tanah.