@book{coleman_coyle_blake_britton_buford_campbell_cox_cregg_daniels_jacobson_et al._2004, title={Production of short rotation woody crops grown with a range of nutrient and water availability: establishment report and 1st-yr responses}, volume={SRS-72}, journal={General technical report SRS-72}, institution={USDA Forest Service, Southern Research Station}, author={Coleman, M. and Coyle, D. and Blake, J. and Britton, K. and Buford, M. and Campbell, B. and Cox, J. and Cregg, B. and Daniels, R. and Jacobson, M. and et al.}, year={2004} }
 @inbook{sanchez_1987, title={Soil productivity and sustainability in agroforestry systems}, ISBN={929059036X}, booktitle={Agroforestry: a decade of development}, publisher={Nairobi: International Council for Research in Agroforestry}, author={Sanchez, P. A.}, editor={H. A. Steppler and Nair, P.K. R.Editors}, year={1987}, pages={205} }
 @article{sanchez_bandy_villachica_nicholaides_1982, title={AMAZON BASIN SOILS - MANAGEMENT FOR CONTINUOUS CROP PRODUCTION}, volume={216}, ISSN={["0036-8075"]}, DOI={10.1126/science.216.4548.821}, abstractNote={Technology has been developed which permits continuous production of annual crops in some of the acid, infertile soils of the Amazon Basin. Studies in Yurimaguas, Peru, show that three grain crops can be produced annually with appropriate fertilizer inputs. Twenty-one crops have been harvested during the past 8½ years in the same field, with an average annual production of 7.8 tons of grain per hectare. Soil properties are improving with continuous cultivation. The technology has been validated by local farmers, who normally practice shifting cultivation. Economic interpretations indicate large increases in annual family farm income and a high return on the investment of chemical inputs. Other promising land use alternatives include low-input crop production systems, paddy rice production in fertile alluvial soils, and pastures or agroforestry in rolling areas. Stable, continuous food crop production is an attractive alternative to shifting cultivation in humid tropical regions experiencing severe demographic pressures. For each hectare of land managed in a highly productive manner, there may be less need for clearing additional tropical forests to meet food demands.}, number={4548}, journal={SCIENCE}, author={SANCHEZ, PA and BANDY, DE and VILLACHICA, JH and NICHOLAIDES, JJ}, year={1982}, pages={821–827} }
 @article{sanchez_couto_buol_1982, title={THE FERTILITY CAPABILITY SOIL CLASSIFICATION-SYSTEM - INTERPRETATION, APPLICABILITY AND MODIFICATION}, volume={27}, ISSN={["0016-7061"]}, DOI={10.1016/0016-7061(82)90019-2}, abstractNote={This paper summarizes the first five years of testing and evaluation of the Fertility Capability Soil Classification System (FCC) and presents an improved version, examples of interpretation and its applicability. FCC is a technical system for grouping soils according to the kinds of problems they present for agronomic management of their chemical and physical properties. It emphasizes quantifiable topsoil parameters as well as subsoil properties directly relevant to plant growth. FCC-classes indicate the main fertility-related soil constraints, which can be interpreted in relation to specific farming systems or land utilization types. Since its publication in 1975, the FCC has been tested, evaluated and put to use in various countries. As a result, the definitions of several modifiers have been changed and additional modifiers have been introduced. Soil maps can be interpreted and redrawn as FCC-units when the necessary data are available. Portions of the FAO/Unesco (1971, 1974, 1977) Soil Maps of the World have been converted to FCC-units with minor difficulties. The system is directly applicable to FAO's (1976) Land Evaluation Guidelines.}, number={4}, journal={GEODERMA}, author={SANCHEZ, PA and COUTO, W and BUOL, SW}, year={1982}, pages={283–309} }
 @misc{sanchez_salinas_1981, title={LOW-INPUT TECHNOLOGY FOR MANAGING OXISOLS AND ULTISOLS IN TROPICAL AMERICA}, volume={34}, ISSN={["2213-6789"]}, DOI={10.1016/S0065-2113(08)60889-5}, abstractNote={The purpose of this chapter is to bring together examples of low-input soil management technology adapted to well-drained, acid, inherently infertile soils of the American tropics classified mainly as Oxisols and Ultisols. Soil taxonomy terminology, including soil moisture regimes, is used. The outcome of the race between world food production and population is determined in the tropics, where most of the world's undernourished people live. The applicability of high-input soil management technologies, however, diminishes in marginal lands where soil and water constraints are not easily overcome at low cost. The rising price spiral of petroleum-related products since has limited the economic feasibility of soil management technologies based on the intensive use of purchased inputs, particularly for farmers with limited resources in the tropics. The term ‘‘low’’ is used in relation to “high”-input technology where the application of fertilizers and amendments largely eliminate chemical soil constraints. The identification of plant species and ecotypes tolerant to the main acid soil stresses allows the development of low-input soil management systems for Oxisol and Ultisol regions where socioeconomic constraints prevent the widespread application of large quantities of lime and fertilizers. The basic approach is to use plants adapted to acid soil constraints, to maximize the use of fertilizers and lime needed to produce about 80% of their maximum yield, and to take advantage of favorable attributes of acid, infertile Oxisols and Ultisols.}, journal={ADVANCES IN AGRONOMY}, author={SANCHEZ, PA and SALINAS, JG}, year={1981}, pages={279–406} }
 @article{sanchez_buol_1975, title={SOILS OF TROPICS AND WORLD FOOD CRISIS}, volume={188}, ISSN={["0036-8075"]}, DOI={10.1126/science.188.4188.598}, abstractNote={The properties and potential of soils of the tropics are poorly understood. The old idea that laterite is formed when tropical soils are cleared is true of only a small proportion of the area. In most features, soils in the tropics are similar or equivalent to soils in the temperate regions. Specifically, soil organic matter contents, commonly believed to be low in the tropics, are essentially similar to those of the temperate regions. While the basic concepts about physical and chemical behavior developed in the nonglaciated temperate regions are directly applicable to the tropics, the development of soil management practices for sustained food production involves different strategies because of environmental and economic constraints. A major distinction is made between the development of high base status and low base status soils. With the former, soil management practices should be aimed at maximizing the potential of high-yielding varieties and improving intercropping systems with relatively intensive fertilizer inputs. With the low base status soils of the vast savanna and jungle areas energy-related inputs should be optimized by (i) selecting of crop varieties and species more tolerant to nutritional deficiencies or toxicities, (ii) applying fertilizers at lower rates than those recommended by classic marginal analysis, and (iii) increasing the efficiency of applied fertilizers in such soils.}, number={4188}, journal={SCIENCE}, author={SANCHEZ, PA and BUOL, SW}, year={1975}, pages={598–603} }
 @article{sanchez_ramirez_calderon_1973, title={RICE RESPONSES TO NITROGEN UNDER HIGH SOLAR-RADIATION AND INTERMITTENT FLOODING IN PERU}, volume={65}, ISSN={["1435-0645"]}, DOI={10.2134/agronj1973.00021962006500040001x}, abstractNote={Abstract}, number={4}, journal={AGRONOMY JOURNAL}, author={SANCHEZ, PA and RAMIREZ, GE and CALDERON, MV}, year={1973}, pages={523–529} }