<![CDATA[Abstrak: Potensi pengembangan padi sawah cukup tinggi pada lahan pasang surut, namun produktivitas padi di lahan ini masih rendah karena rendahnya tingkat kesuburan tanah, terutama hara P dan bahan organik. Penelitian dilaksanakan di lahan rawa pasang surut Desa Sungai Solok, Kabupaten Pelalawan, Provinsi Riau dengan tujuan mendapatkan rekomendasi pemupukan dari kombinasi pupuk P dan ameliorasi kompos jerami padi. Perlakuan ditata dalam Rancangan Split Plot dengan tiga ulangan. Petak utama adalah dosis posfat (P) yakni 30; 60; 90; 120 kg P2O5 ha-1 yang bersumber dari TSP, sedangkan anak petak terdiri atas dosis pupuk organik (O) yang berasal dari kompos jerami padi dengan dosis: 1,0; 2,0; dan 3,0 t ha-1. Parameter yang diamati adalah (i) sifat kimia tanah meliputi pH, C-organik, P-tersedia, (Ca, Mg, K, dan Na)-tertukar, dan KTK, diukur sebelum pemupukan dan (ii) produktivitas padi. Hasil penelitian menunjukkan bahwa tanah di lokasi penelitian bereaksi sangat masam dengan kadar C-organik dan P-tersedia rendah, kadar N-total sedang, dan kadar unsur-unsur basa dan KTK tergolong rendah. Dosis kompos jerami padi, dosis pupuk P dan interaksinya berpengaruh terhadap produktivitas padi di lahan pasang surut tipe B. Produktivitas tertinggi (5,73±0,49 t ha-1) dihasilkan dari pemberian kompos jerami padi 2,0 t ha-1 yang dikombinasi dengan 60 kg P2O5 ha-1.Abstract. The potential for the development of paddy rice on tidal swamp land is relatively high, however, rice yield on this land is low due to low soil fertility, especially because of low phosphorus (P) and low organic matter in the soil. The experiment was conducted in the tidal swampland at Sungai Solok Village, Pelalawan Regency, Riau Province with the objectives of developing P fertilizer in combination with organic matter recommendation. The treatments were arranged in a split plot design with three replications, where rice straw compost was the main plot, and P fertilizer as the subplot. The main plot was P fertilizer rates: 30; 60; 90; 120 kg P2O5/ha in the form of TSP. The sub-plot was organic matter (O) in the form of rice straw compost at rates: 1.0 ; 2.0 ; 3.0 t ha-1. Observations consisted of (i) soil chemical properties including soil pH, organic C, available P, excangeable Ca, Mg, K, and Na, and cation exchange capacity (CEC), measured before fertilization and (ii) crop yield. The results showed that the soil was very acid with low levels of organic C and available P, while the total N was moderate, and basic cation contents and CEC were low. The rate of rice straw compost, P fertilizer and interaction of the two affected the productivity of rice in the tidal swampland. The highest productivity (5.73±0.49 t ha-1) was produced from the treatment of 2.0 t ha-1 composted rice straw in combination with 60 kg P2O5 ha-1.]]>
