Performance Indices of a Combined Tillage Machine for the Incorporation of Leguminous Green Manure at Appropriate Depth

Abstract

Background: The decomposition rate of biomass depends significantly on soil properties and on the design of the machine used for incorporation. Well-chopped biomass, incorporated in a productive zone with uniform mixing, gives better results instead of placing longer stalks on or near the field surface. Methods: In the field experiments conducted during 2017 and 2018, interaction of soil and biomass, placed at various depths in sandy loam soil, was studied 10, 20, 30, 40, 50, 60 and 90 days after incorporation (DAI). Further, mechanical incorporation of green manure crop with innovative two-bottom combined tillage machine, namely biomass incorporator, was studied at different levels of soil type, plant height, forward speed and rotor speed.Result: The depth range of 70-140 mm was found most appropriate for incorporation to achieve a higher decomposition rate. Plant stem of 50 days old dhaincha (Sesbania aculeata) crop decomposed by 13.0, 31.5, 29.25, 24.25 and 22.05% at depth range 0-70 (D1), 70-140 (D2), 140-210 (D3), 210-280 (D4) and 280-350 (D5) mm, respectively 10 DAI. About 55% of the biomass, incorporated at depth range D2, got decomposed 40 DAI. The average depth of placement of biomass with biomass incorporator ranged between 92 and 131 mm. The soil pulverization index and crop mixing index with the machine varied from 3.58 to 30.65 mm and 93.62 to 98.05%, respectively. The surface profile coefficient with the machine ranged between 24.2 and 50.6 mm. The efficient mixing of the biomass into the soil with thorough coverage of pulverized soil was achieved with rational field undulation.