Karakteristik dan optimalisasi tanah sawah di sentra produksi beras solok, Sumatera Barat

Abstract

Solok is known as Rice Production Center which Cisokan as one of the supreme paddy varieties. Presently, the average of Cisokan production reach 4.15 tonnes/ha and varies among the parent materials, while the highest production reach 7.08 tonnes/ha dry milled unshelled rice. This showed Cisokan production not optimal. For this reason, research has been done to optimize Cisokan production in each parent material. Results showed that optimal management for paddy soil derived from volcanic material is: urea 200 kg/ha, SP-36 500 kg/ha and KCl 50 kg/ha, the paddy soil derived from river sediment is: urea 100 kg/ha, SP-36 500 kg/ha and KCl 50 kg/ha, and the paddy soil derived from lake sediment is: urea 300 kg/ha, SP-36 100 kg/ha and KCl 100 kg/ha. The highest production reach 7.52 tonnes/ha, 6.47 tonnes/ha and 6.91 tonnes/ha dry milled unshelled rice, respectively. The application of optimal management on different soil characteristic, the criteria of land suitability for Cisokan variety have been made for each parent materials. The lesser land characteristics data needs bring through the land evaluation process easier, faster and cheaper with better results. Land characteristics that are needed to evaluate the Cisokan land use types in volcanic regions consist only of the clay content, available P2O5 and the Ca/K ratio. The paddy field in the Alluvial Plain required the clay content, total N, available P2O5, and CEC of clay. While the paddy field in the Lacustrine Plain required total N, available P2O5, Mg/K ratio and CEC of clay.

Solok dikenal sebagai Sentra Produksi Beras. Beras yang dihasilkan, disamping mensuplai kebutuhan pangan masyarakat Sumatera Barat, juga masyarakat di luar Sumatera Barat, seperti Riau dan Jambi. Sentra Produksi Beras Solok berada pada ketinggian 365-1.250 m d.p.l., menempati lereng tengah volkanik Gunung Talang, Dataran Aluvial Batang Sumani hingga Dataran Lakustrin Danau Singkarak. Cisokan adalah salah satu varietas padi sawah unggulan Sentra Produksi Beras Solok. Saat ini rata-rata produksi Cisokan baru mencapai 4.15 ton/ha, sementara produksi tertinggi mencapai 7.08 ton/ha Gabah Kering Giling (GKG). Ini menunjukkan produksi Cisokan di Sentra Produksi Beras Solok belum optimal. Dataran Aluvial dan Lakustrin terbentuk dari bahan endapan (Alochthonous materials). Di daerah volkanik tanah terbentuk dari bahan in situ (Autochthonous materials). Hasil penelitian lapang menunjukkan rata-rata produksi Cisokan di Dataran Lakustrin hanya 3.37 ton/ha, di Dataran Aluvial 4.46 ton/ha dan di daerah volkanik 4.39 ton/ha GKG. Hal ini menunjukkan bahwa masing-masing bahan induk mempunyai potensi berbeda, sehingga untuk mengoptimalkan produksi Cisokan perlu tindakan pengelolaan yang berbeda pula.