Pustaka Ilmiah Universitas Padjadjaran

Abstrak

Water Saving And Reducing Inorganic Fertilizers Technology For Increasing The Soil Biological Activity And Rice Productlvity In System Of Organic Based Aerobic Rice Intensification (SOBARI)

As a main food crops in Indonesia, rice is belong to the most important grains and has a significant role on political. economical and social issue. Rice production is dominated by permanent flooding or inundation system. Intensification of permanent flooding (anaerobic) of paddy soils not only reduces the soil biological power significantly, but also restricts the roots growth. Virtually water to produce one kilogram of rice in continuously irrigated fields needs approximately 3,000 L of water, while the theoretical minimum at the crop scale is as low as 600 L. Under anaerobic condition, soil organisms cannot growth optimally and estimated only about 25% rice roots can growth normally. Intensive use of inorganic fertilizers, particularly N fertilizers such as urea accelerates the mineralization of soil organic matter. Consequently. soil organic content decreases rapidly. It is an indication that the rice production received high inorganic fertilizers dosage has reached a leveling off and caused the decreasing of soil quality and soil health. To increase the rice production and revitalize the soil quality and soils health can be reached by using the soil biological power in system organic based of aerobic rice intensification {50BARD. SOBARI is a holistic rice production system. by using and integrating the soil biological power, plant, fertilizers and water management according to the plan and design (by design). Composted straw or incorporating of 5 ton per ha is used as organic fertilizers to enhance the soil organic content, activity of beneficial microbes in soils and to reduce the inorganic fertilizers by at least 25%. The field results using various rice varieties in several Provinces of Indonesia revealed that the SOBARI can produce grain yield about 8 – 12 t/ha (average of an increasing about 50 — 150% compared to anaerobic rice cultivation) and the water irrigation was reduced by at least 30 – 50%. This high rice yield is highly correlated with the increasing of roots zone about 4 — 10 times, number of productive tillers about 60 — 80 tillers, number of panicles, length of panicles and number of grainipanicle. and as well as due to the increase of soil biodiversity (beneficial organism) under aerobic condition.