Effect of Electric Furnace Slag, Dolomite, and Micro Nutrient on Chemical Soil Properties, Growth and Yield Rice on Peat Soil from Kumpeh, Jambi

Abstract

In 2010 production of 66,41 million tons of rice was not able to fulfill the demand for rice. Limited of productive land causes agricultural extensive conducts on marginal lands, such as peat land. Naturally Indonesian peat lands are low nutrient content and very acid. This problem can be solved by liming, addition of macro and micro nutrients, and addition an ameliorant material: steel slag, volcanic ash, sludge, etc. One of ameliorant used for agriculture in America, Japan, Korea is steel slag, but this material has not been used in Indonesia. Whereas in previous research result showed the steel slag (electric furnace slag) Indonesia have increase soil pH, exchangeable Ca and Mg, and increase availability of Si in soil. The objective of this research was to evaluate effect of electric furnace slag (EF slag), dolomite, and micro nutrients on chemical properties of soil and rice growth and yield on peat soil. This research consisted of two experiments; incubation in laboratory and green house pot experiment, using pot soil from Kumpeh Hulu, Jambi. The dosages applied ware EF slag 0%, 2%, 4%, 6%, 8% and for dolomite equivalent to EF slag 0%, 2%, 4%, 6%, 8%. Experimental design used was completely randomized design. The result indicated that addition of EF slag significantly increased soil pH, exchangeable Ca and Mg, available P, SiO2, and micro nutrients (Fe, Mn, and Zn). The addition of dolomite significantly increased soil pH and exchangeable Ca and Mg. The addition of micro nutrient only significantly increased available of Cu and Zn. However, all treatments have no significant effect on N-total and heavy metal content (Pb, Hg, and Cd). Electric furnace slag and dolomite significantly increase growth of rice, but only EF slag which significantly increased production of rice. The effect of EF slag showed significantly better than applied of dolomite and micro nutrients for growth and production of rice on peat soil from Kumpeh, Jambi. The content of toxic heavy metals (Pb, Hg, and Cd) in brown rice was lower than maximum limit of heavy metal in brown rice. Consequently, the brown rice is safe to consume.

Pada tahun 2010 produksi padi sebesar 66,41 juta ton padi (gabah kering giling) dirasa belum mampu memenuhi kebutuhan beras. Keterbatasan lahan produktif menyebabkan ekstensifikasi pertanian mengarah pada lahan-lahan marjinal, salah satunya yaitu lahan gambut. Secara alamiah lahan gambut di Indonesia memiliki tingkat kesuburan rendah karena kandungan unsur hara yang rendah dan bersifat sangat masam. Upaya yang dilakukan untuk mengatasi masalah tersebut antara lain adalah pengapuran, penamban unsur hara makro dan mikro, serta penambahan bahan-bahan amelioran seperti: terak baja, abu vulkan, lumpur rawa, abu sisa pembakaran, dan lain-lain. Salah satu amelioran yang umum digunakan di Amerika, Jepang, dan Korea yaitu terak baja, tetapi di Indonesia belum digunakan. Padahal hasil penelitian sebelumnya menunjukkan bahwa terak baja (electric furnace slag) Indonesia dapat meningkatkan pH tanah, Ca dan Mg dapat dipertukarkan, dan meningkatkan ketersediaan Si dalam tanah. Penelitian ini bertujuan untuk mengetahui pengaruh electric furnace slag (EF Slag), dolomit, dan unsur mikro terhadap sifat kimia tanah serta pertumbuhan dan produksi tanaman padi pada tanah gambut. Penelitian dilakukan melalui percobaan inkubasi di laboratorium dan percobaan pot di rumah kaca dengan menggunakan tanah gambut yang berasal dari Kumpeh, Jambi. Dosis yang diberikan yaitu EF Slag 0%, 2%, 4%, 6%, dan 8% dan dolomit ekuivalen EF Slag 0%, 2%, 4%, 6%, dan 8%. Rancangan percobaan yang dipakai adalah rancangan acak lengkap (RAL).