@article{alegre_cassel_amezquita_1991, title={TILLAGE SYSTEMS AND SOIL PROPERTIES IN LATIN-AMERICA}, volume={20}, ISSN={["0167-1987"]}, DOI={10.1016/0167-1987(91)90037-X}, abstractNote={A review of tillage systems in Latin America revealed that considerable research on this topics has been done and much is currently in progress. Results of most of this tillage research, however, have not been published in international refereed journals, thus making it difficult to assess the current state of the art on this topic. A high percentage of tillage research results has not been published at all. In general, conservation tillage practices, that is, those commonly referred to as no-till and minimum till, had higher bulk densities in the surface soil, but lower macroporosities, infiltration rates and crop yields as compared with conventional tillage, which was typically disk plowing. Chisel plowing and subsoiling, deep tillage practices whose action extends below the usual depth of disk plowing, usually decreased mechanical impedance, improved root penetration and increased crop yields. Soil loss from cropped land was usually greatest under conventional tillage unless mulch was applied to the soil surface. We believe that some form of tillage practice that mixes the surface soil layer will have to be incorporated from time to time into any tillage system to maintain soil conditions adequate for sustained continuous cropping.}, number={2-4}, journal={SOIL & TILLAGE RESEARCH}, author={ALEGRE, JC and CASSEL, DK and AMEZQUITA, E}, year={1991}, month={Jun}, pages={147–163} }
 @article{alegre_cassel_bandy_1990, title={EFFECTS OF LAND-CLEARING METHOD AND SOIL-MANAGEMENT ON CROP PRODUCTION IN THE AMAZON}, volume={24}, ISSN={["1872-6852"]}, DOI={10.1016/0378-4290(90)90026-8}, abstractNote={The success of intensive, continuous cropping of newly cleared land in the humid tropics is highly dependent upon the method of land clearing and subsequent soil management. The objective of this study was to evaluate the effect of different land-clearing regimes, including initial tillage after clearing and subsequent soil management, on crop performance on an Ultisol in the Amazon Basin of Peru. The study was conducted on a Yurimaguas soil (fine-loamy, siliceous, isohyperthermic Typic Paleudult) covered by a 20-year-old evergreen forest which was cleared at the start of the experiment. Land-clearing treatments included slash and burn, bulldozing with a straight blade, and bulldozing with a shear blade. Post-clearing tillage methods were chisel-plowing and disking. Post-clearing soil management practices (subplots) included: (1) flat-planted, no fertilizer or lime added; (2) flat-planted, fertilizer and lime incorporated; and (3) soil bedded at a 1.1-m spacing and fertilizer and lime applied, as in subplot 2. The cropping sequence was upland rice [Oryza sativa L.]-soybean [Glycine max (1.) Merr.]-corn [Zea mays L.]-rice-corn. In general, all crops showed a positive response to the post-clearing tillage practices of chiseling and disking. The post-clearing soil-management practice combining fertilization, liming, and bedding generally produced the highest yields of rice and corn. The greatest average relative grain-yields, in descending order, were produced by the following management systems: slash/burn/flat-plant/fertilizer/lime (94% average relative grain-yield)slash/burn/bedded/fertilizer/lime (90%)shear-blade/burn/disk/bedded/fertilizer/lime (88%)shear-blade/burn/disk/flat-plant/fertilizer/lime (86%).}, number={1-2}, journal={FIELD CROPS RESEARCH}, author={ALEGRE, JC and CASSEL, DK and BANDY, DE}, year={1990}, month={Aug}, pages={131–141} }