PEMBERDAYAAN SUMBERDAYA HAYATI TANAH UNTUK REHABILITASI TANAH ULTISOL TERDEGRADASI - G., Subowo (Indonesian Center for Agriculture Land Resource Development, 2012)
Abstrak. Ultisol merupakan salah satu tanah tua, terdapat horizon argilik/iluviasi yang padat, mengalami pencucian intensif, tanah lapisan atas tipis, kesuburan rendah, dan tanah banyak mengalami degradasi. Sejalan permasalahan tersebut, upaya rahabilitasi tanah Ultisol terdegradasi di kawasan megabiodiversity seperti halnya di Indonesia dapat diupayakan dengan pemberdayaan sumberdaya hayati tanah. Fauna tanah yang mampu membuat liang di dalam tanah dapat mengurangi erosi dan pencucian hara, mikroba pelarut P dapat meningkatkan ketersediaan P tanah, mikroba penambat N2-bebas dapat meningkatkan ketersediaan hara N tanaman, dan pengkayaan populasi organisme tanah lainnya untuk meningkatkan daur hara dan konservasi C-organik tanah. Untuk mewujudkan peranan organisme tanah tersebut perlu diikuti pemberian bahan organik ataupun pupuk sebagai sumber hara dan energi, serta pengendalian jenis dan jumlah populasi organisme tanah yang memiliki peranan penting dalam memperbaiki kesuburan tanah sesuai dengan target perbaikan yang diharapkan.Abstract. Ultisol is one of the highly weathered soils, with solid agrillic or illuvial horizon, intensive leaching, a thin top layer, low fertility, and a lot of soil degradation. Along these problems, attempts to rehabilitate degraded Ultisols in megabiodiversity areas like Indonesia could be performed by empowering soil biological resources. Soil fauna having ability to create soil pores could reduce erosion and nutrient leaching, microbes have ability to dissolved P and P-availability, microbes able to fix N2 from atmosphere to increase soil nutrient, and the enrichment of populations of other soil organisms to improve nutrient cycling and soil C-organic preservation. To achieve the role of soil microorganisms, it is necessary to apply organic matter as sources of nutrients and energy, controlling the type and number of populations of soil organisms which have an important role in improving soil fertility according to the expected targets.