The objective of this research was to evaluate the vegetative development in 3 North Sulawesi local rice varieties (Superwin (A), Temo (B) dan Burungan (C)) as a response to the thickness variation of cultivated soil layer combined with irrigation deletion. This research was conducted in the glasshouse using polyvinyl chloride (PVC) column (500 mm height, 125 mm diameter) as pots. The treatments consisted of 3 variations of cultivated soil layer, i.e. 18, 24 and 30 cm and the clay hardpan was placed below each of the cultivated soil layers. The level of irrigated water and the amount of the fertilizer were applied following the method of SRI (System of Rice Intensification). The results showed that reducing the thickness of cultivated soil layer to 18-24 cm saved the water as much as 6.15-8.12 L (29.7-39.2%) per pot compared with 30 cm thickness of soil layer in Burungan. Comparing with the 24 cm soil layer thickness, the treatments of 18 cm thickness saved 6.92 L (23.42%) and 5.77 L (18.32%) water, respectively in Superwin and Temo.
ABSTRAKTujuan penelitian ini untuk mengkaji pengaruh pengurangan ketebalan tanah olah sekaligus pengurangan volume air yang tersimpan terhadap perkembangan vegetatif pada 3 varietas padi lokal di Sulawesi Utara (Superwin (A), Temo (B) dan Burungan (C)). Penelitian dilaksanakan di rumah kaca dengan menggunakan pot polyvinyl chloride (PVC) setinggi 500 mm dan berdiameter 125 mm. Perlakuan dalam penelitian ialah 3 variasi ketebalan tanah olah, yaitu 18, 24 dan 30 cm. Untuk mensimulasikan seperti keadaan di lapangan, maka di bawah lapisan olah ini diisi dengan tanah liat yang telah dipadatkan. Aplikasi pemberian air dan pemupukan mengikuti pola tanam baku SRI. Hasil uji statistik Anava yang dilanjutkan dengan BNT 5% menunjukkan penurunan ketebalan lapisan tanah olah hingga 18 cm berpotensi dapat menghemat air sebanyak 6,15 L (29.7%) per pot dibandingkan dengan ketebalan 30 cm selama pertumbuhan fase vegetatif pada varietas Burungan. Dibandingkan dengan perlakuan ketebalan tanah olah 24 cm, ketebalan tanah olah 18 cm dapat menghemat air 6.92 L (23.42%) dan 5.77 L (18.32%) berturut-turut untuk varietas Superwin dan Temo. Kata kunci: irigasi hemat air, padi lokal Sulawesi Utara, System of Rice Intensification Eugenia