海量图书期刊资源,随时随地畅享阅读乐趣
Soil Structure and Moisture MovementHarper, Horace J. · Soil Science Society of America Journal · 1938
THE DETERMINATION OF AMMONIA IN SOILSHARPER, HORACE J. · Soil Science · 1924
AN IMPROVED SOIL SAMPLING TUBEHARPER, HORACE J. · Soil Science · 1931
Chemical Composition of Certain Aquatic PlantsHorace J. Harper and Harley A. Daniel · Botanical Gazette · 1934
Conservation of Natural Resources, 2nd EditionHarper, Horace J. · Agronomy Journal · 1959
Soil-Plant Relationshipsby C. A. BlackReview by: Horace J. Harper · Bios · 1958
The Accurate Determination of Nitrates in Soils.Harper, Horace J. · Industrial & Engineering Chemistry · 1924
Report of Committee on Exchange of Soil ProfilesBenton, T. H.; Kellogg, C. E.; Krusekopf, H. H.; Lee, L. L.; Lutz, J. F.; Veatch, J. O.; Harper, Horace J. · Soil Science Society of America Journal · 1935
Soil Science and GeographyEkblaw, W. Elmer · Soil Science Society of America Journal · 1937
Soil Science and EngineeringTrullinger, R. W. · Soil Science Society of America Journal · 1937
Soil Science and Mineralogy1Marshall, C. E. · Soil Science Society of America Journal · 1937
Availability of Plant NutrientsHibbard, P. L. · Soil Science Society of America Journal · 1937
Fertilized Check PlotsMetzger, J. E. · Soil Science Society of America Journal · 1937
Method of Recording Soil DataNikiforoff, C. C. · Soil Science Society of America Journal · 1937
Nomenclature of Forest Humus LayersHeiberg, S. O. · Soil Science Society of America Journal · 1937
Technology of Erosion ControlNichols, M. L. · Soil Science Society of America Journal · 1937