Pengaruh pemberian bahan organik jerami padi terhadap kehilangan fosfat dan ferro di tanah sulfat masam

FAHMI, Arifin, Prof. Dr. Bostang Radjagukguk, M.Agr.Sc

2008 | Tesis | S2 Ilmu Tanah

Penelitian Lni bertujuan untuk mengetahui pengaruh pemberian bahan organik jerami padi terhadap ketersediaan P dalam tanah, serta kehilangan fosfat dan Fe^^ melaluui pelindian dari tanah sulfat masam. Sebuah percobaan tiga faktor dilaksanakan di rumah kaca dengan rancangan acak lengkap dan tiga uiangan. Faktor pertama adalah kondisi tanah yakni selama lima tahun terakhir selalu diberikan bahan organik Jerami padi dan yang tidak pernah diberikan bahan organik Jerami padL Faktor kedua adalah pemberian bahan organik Jerami padi aitu dengan pemberian dan tanpa pemberian bahan organik Jerami padi, sedangkan faktor ketiga adalah pemupukan P yang terdiri atas 3 aras takaran pupuk SP 36. Pengamatan dilakukan terhadap P tersedia, Fe tertukaran, pH, P total C organik dan Eh untuk tanah ; fosfat, Fe dan pH untuk air lindian, sedangkan untuk tanaman adalah tinggi tanaman, jumlah anakan dan skor keracunan Fe. Pengamatan dilaksanakan pada 2, 4, 6 dan 8 minggu setelah tanam (MST). Berat kering tanaman dan kandungan P dalam Jaringan tanaman ditentukan pada 8 MST. Hasil penelitian menunjukakn bahwa interaksi 3 faktor berpengaruh nyata terhadap pH dan Eh tanah pada 2 MST, sedangkan interaksi antara pemberian bahan organik dan kondisi tanah berpengaruh nyata terhadap pH tanah, P tersedia dan P total pada 4, 6 dan 8 MST. Interaksi antara pemberian bahan organik dan takaran pemupukan P berpengaruh nyata terhadap pH dan Eh tanah pada 4 MST, serta P tersedia pada 8 MST. Faktor utama pemberian bahan organik berpengaruh nyata terhadap Fe tertukaran, pH tanah dan konsentrasi Fe dalam air lindiandan pada semua periode pengamatan, terhadap Eh tanah pada 6 dan 8 MST, dan terhadap Jumlah anakan tanaman padi pada 2, 4 dan 6 MST sedangkan terhadap tinggi tanaman berpengaruh nyata pada 2 dan 4 MST. Faktor utama lainnya yang berpengaruh nyata adalah kondisi tanah terhadap Eh tanah pada 6 dan 8 MST, dan terhadap Jumlah anakan pada 4 MST. Berdasarkan skoring tingkat keracunan Fe, disimpulkan bahwa tamanan padl dalam percobaan Lnl tidak mengalaml keracunan Fe. Kata kuncl: Jerami padi, Fosfat, Ferro dan Tanah sulfat masam

The objective of the experiment was to investigate the effect of application of organic matter consisting of rice in as well as phosphate and Fe^^ loses from the acid sulphate soils. An experiment was conducted in the glass house consisting of the three treatment factors using the completely randomized design with three repUcation. The first factor was soil condition consisting of continuous application of rice straw and without application of rice rice straw during the last 5 years. The second factor was fresh application of rice straw consisting of with application and without application, whereas the third factor was P application consisting 3 rates of SP - 36 fertilizers. Soil parameter were available P, exchangeable Fe, pH, total P, organic Q and Eh whilst lechate parameters measured were phosphate, Fe and pH, whereas plant parameter measured consisted of plant height tiler number and Fe toxicity score. Measurement were conducted at 2,4, 6 and 8 weeks after planting. Plant dry weight and P concentration in plant tissue were determined at 8 week after planting. The result showed the three factors interaction had a significant influence on soil pH and Eh at 2 weeks after planting, whilst interaction between rice straw application and soU condition had a significant influence on soil pH, available P and total P at 4, 6 and 8 weeks after planting. The interaction between rice straw application and P fertilizers rate had a significant influence on soil pH and Eh at 4 weeks after planting, and on available P at 8 weeks after planting. The main effect of rice straw application was significant on exchangeable Fe, Fe concentration lechate and soil pH at all observations periods, on soil Eh at 6 and 8 weeks after planting, and on the tiller number of the rice plant at 2, 4 and 6 weeks after planting, whereas significant on plant height was obsen^ed at 2 and 4 weeks after planting. Another significant mam factor effect was that of soil condition and soil Eh at 6 and 8 weeks after planting, and on the tiller number at 4 weeks after planting. Based on the scoring of degree of Fe toxlcity, it was concluded that the rice plant did not exhibit any effect of Fe toxicity. Key words: Rice straw. Phosphate, Ferro, Acid sulphate soils

Kata Kunci : Jerami padi,Fosfat,Ferro dan tanah sulfat masam