Kombinasi Optimal cara Olah Tanah daD Tingkat Pengapuran untuk Pola Tumpangsari Jagung di antara Karet pada Tanah Podzolik Marah Kuningl
Abstract
Technical m./ftijication of rubber based intercroppiv system are still needed due to the appearance of vari!s - problems, either bio-physical or socio-economie,factorsA. t different areas, where labour is limited; substitution of - manual tillage and manual seeding with mechanical equipment and manual weed control with chemical control has to be taken into account. Researcho n rubber basedi ntercropping,c ommbiningt wo tillage systems.c. onventionalo r full tillage, where soil was plowed and harrowed 2 and 2 times respectively,. and reduced tillage where soil tillage was .A done only one plowing and one harrowing andfour liming levels atintercrop' rows at 20 cm wJth (maize, variety ofC7) ',r wasc arried out in SembawaR esedchIn stitute since 1998. Thep resentedd ata were collectedt illage systema nd liming - dose was observed, howev)r the grain yield difference was reduced up to 22%. During dry season cowpea (Vigna - anguikulata), planted after maize, produced 870 kg/ha. The cost of production of cropping maize as rubber' intercrop usingf ull tillage systema t optimal liming level was about.R' p. 2,1 million. If the grain price is Rp. 1200/kg,t hen the break-evenp oint will be reacheda t grain yield of 1750k g/Ira. Rubberg ro)/th of IRR 39 clone, a latex and timber clone, - wasv ery good. Until 13 months,s temd iameterw asn ot affectedb y tillage systemsa nd levelso f liming for intercrop.