Savanna Ecosystems In Tropical South America: Findings From A Computerized Land-Resource Survey,
2026
CIAT
Savanna Ecosystems In Tropical South America: Findings From A Computerized Land-Resource Survey, T T. Cochrane
IGC Proceedings (1977-2023)
A land-resource survey is being made in tropical South America with the objective of creating a base for development and transfer of improved food-crop and pasture-plant germ plasm-based technology. Preference was given to study of the 200 million ha of native savannas, although the survey now stretches across the Amazon forests to southern Brazil. Land information is reduced to a common base, with land systems defined as repetitive patterns of climate, landscape, and soils. They are delineated directly onto satellite and side-looking radar imagery following field work and climatic analyses. Within land systems the vegetation and soils are separately described …
Effects Of Topsoil Depths And Species Selection On Reclamation Of Coal-Strip-Mine Spoils,
2026
USDA-SEA-AR
Effects Of Topsoil Depths And Species Selection On Reclamation Of Coal-Strip-Mine Spoils, W J. Mcginnies, P J. Nicholas
IGC Proceedings (1977-2023)
The research objectives were (1) to determine the effects of topsoil on establishment of seeded vegetation on strip-mine spoils, (2) to determine the effects of depth of topsoil placed over spoil on growth of herbage and roots, and (3) to evaluate 17 grass species grown on topsoil and mine spoil. In a field study in northwestern Colorado, a seed mixture of range grasses, forbs, and shrubs was drilled on five (0, 10, 20, 30, and 46 cm) depths of topsoil placed over surface coal-mine spoil, and the effect of topsoil depth on species establishment was measured. In a greenhouse study, …
Progress In Development Of Conservation Plant Cultivars By The Usda Soil Conservation Service,
2026
USDA, SCS
Progress In Development Of Conservation Plant Cultivars By The Usda Soil Conservation Service, H W. Everett
IGC Proceedings (1977-2023)
The USDA Soil Conservation Service (SCS) operates a coordinated network of 22 plant materials centers in the U.S.A. to assemble, evaluate, select, cooperatively release, and provide for the commercial increase of native and introduced plants for the conservation and improvement of soil, water, and related resources. Standardized procedures have been developed and are being used for this comparative plant-testing program. Evaluation data can be retrieved from an automatic data-processing system through standardized reports. Over 140 SCS-released cultivars of conservation plants are available commercially for use in range, pasture, and other grassland improvement to reduce sediment movement and improve wildlife habitat. …
Pasture Production And Changes In Soil Fertility On A Long-Term Irrigated Superphosphate Trial At Winchmore, New Zealand,
2026
Ministry of Agriculture and Fisheries, NZ
Pasture Production And Changes In Soil Fertility On A Long-Term Irrigated Superphosphate Trial At Winchmore, New Zealand, B F. Quin, D S. Rickard
IGC Proceedings (1977-2023)
The Winchmore trial was commenced in 1952 to investigate the superphosphate requirements of irrigated ryegrass-white clover pasture under grazing. Treatments receiving 0, 188, and 376 kg/ha annually of single superphosphate have produced average annual yields of 4.3, 10.0, and 11.2 metric tons (t)/ha dry matter, respectively. The control production is being maintained by continuing weathering of soil P and by the input of S in irrigation water and rainfall. Topsoil organic C, N, and S reached plateaus on all treatments after 10-15 years. Organic P (P0) showed a linear increase on all treatments until the trial was limed (4 t/ha) …
Soil Nutrient Constraint For Legume-Based Pastures In The Brazilian Cerrados,
2026
CIAT
Soil Nutrient Constraint For Legume-Based Pastures In The Brazilian Cerrados, W Couto, C Sanzonowics
IGC Proceedings (1977-2023)
Soil-nutrient deficiencies in two cerrados soils have been investigated as a preliminary to small-plot research oriented to estimate fertilizer requirements for establishment of legumes in grass-legume associations. The studies were conducted in the greenhouse, in 2-kg pots, with surface-soil samples taken from two sites representative of the dominant soils in the region. These are the dark red latoso1 (DRL) and the red-yellow latosol (RYL), which qualify as Haplustox and Acrusto:,:, respectively. Two kinds of e:,:periments were carried out. One consisted of a 1/4 replicate of a 28 factorial including potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), zinc (Zn), molybdenum …
Prediction Of The Supply Of Soil Nitrogen To Grass,
2026
The Grassland Institute, UK
Prediction Of The Supply Of Soil Nitrogen To Grass, D C. Whitehead
IGC Proceedings (1977-2023)
Predictions of the supply of soil nitrogen (N) to grass over a growing season requires an assessment of nitrate N plus ammonium N (1) present in the soil at the beginning of the season and (2) likely to be released from the potentially mineralizable organic N during the season. Although a number of methods have been proposed for predicting soil N supply, and in particular the component arising from the potentially mineralizable N, many are too time consuming for routine use, and others have not been proven effective over a range of soils. However, in recent studies, the measurement of …
Phytotoxic Response Of Five Range-Grass Species To Six In-Situ Fossil-Fuel Retort Waters,
2026
University of Wyoming
Phytotoxic Response Of Five Range-Grass Species To Six In-Situ Fossil-Fuel Retort Waters, O D. Skinner, J C. Sexton, T S. Moore, D S. Farrier
IGC Proceedings (1977-2023)
Oil shale, tar sands, and undergrowid coal gasification represent viable sources of fossil fuel to assist in meeting U.S. energy needs. Development of fossil-fuel-processing technologies has progressed to a point where commercialization may soon become a reality. Concurrent with this development must be the assessment and solution of environmental problems. A particular and significant problem resides in the handling, containment, treatment, disposal, use, and eventual fate of waters recovered with the oil, gas, and subsurface waters associated with synfuel-processing techniques. The magnitude of plant responses and potential phytotoxic effects resulting from exposure to these produced waters have not been evaluated, …
Suitability Of Early Pleistocene Sandy Lowlands For The Cultivation Of Alfalfa (Medicago Sativa L.),
2026
GDR
Suitability Of Early Pleistocene Sandy Lowlands For The Cultivation Of Alfalfa (Medicago Sativa L.), E Wojahn, G Mundel, W Kreil
IGC Proceedings (1977-2023)
The areas with sandy soils in the Pleistocene lowland of the GDR are being ameliorated on a large scale. In these lowlands, low bogs appear together with hydromorphic sandy soils. The latter are situated higher above the groundwater level. Because of the lowering of groundwater by drainage, these sandy soils are no longer suitable for intensive and high-yielding grass cultivation. Especially during summer the comparat:i.vely shallow-rooted grasses cannot gain their water requirement from ground water. Therefore, we investigated whether and under what conditions higher and more reliable forage yields could be obtained on such soils by cultivation of the deeper-rooted …
Impact Of Phosphorus And Potassium Fertilization On Maintaining Alfalfa-Orchardgrass Swards In Hokkaido, Japan,
2026
Hokkaido University
Impact Of Phosphorus And Potassium Fertilization On Maintaining Alfalfa-Orchardgrass Swards In Hokkaido, Japan, H Oohara, N Yoshida, K Fukunaga, W G. Colby, M Drake, W F. Wedin, G Kemmler, H R. Uxekull, M Hasegawa
IGC Proceedings (1977-2023)
In spite of the importance of alfalfa for all kinds of livestock, particularly for dairy cattle, the cultivation of alfalfa has not yet expanded in Hokkaido, Japan. A comprehensive research project has been undertaken, based on observations oflong-term'effects of fertilization on longevity and productivity of alfalfa-orchardgrass mixtures. This report is concerned with (1) the drymatter production of alfalfa and orchardgrass, cultivars of which were introduced from the U.S.A. and (2) the ratio of alfalfa to orchardgrass and uptake of nitrngen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg). The research began in 1960 and is continuing with close …
Residual Effects Of Two Years Of Very High Nitrogen Applications On Clay Soil Under Grass In A Humid Temperate Climate,
2026
Institute for Soil Fertility
Residual Effects Of Two Years Of Very High Nitrogen Applications On Clay Soil Under Grass In A Humid Temperate Climate, W H. Prins
IGC Proceedings (1977-2023)
In recent field trials on all-grass swards on clay soils, fertilizer rates of 480 kg/ha and higher showed distinct residual effects in the following year. This paper analyzes the considerable residual effects of one treatment on heavy clay soil over 2 experimental years, after very high rates of N had been applied during 3 pretreatment years (totaling 800 kg N or more/ha/yr). The residual effect was measured through the increase in yield over a reference treatment, at one rate of N application ( 40 kg N/ha/cut, totaling 200 and 240 kg N/ha in the first and second experimental years, respectively). …
Liming For Tropical Legume Establishment And Production,
2026
University of Florida
Liming For Tropical Legume Establishment And Production, G H. Snyder, A E. Kretschmer Jr
IGC Proceedings (1977-2023)
Liming has been declared unnecessary for tropical legume production because tropical legumes (1) are efficient in extracting Ca from soils and are tolerant of excess Al, Fe, and Mn, and (2) are readily nodulated by alkali-producing Rhizobium that can function in acid soils. Numerous research reports from Australia, Uganda, Brazil, and Colombia lend credence to this thinking, since no lime responses were observed in those studies. In other work, liming actually depressed tropical legume growth. However, positive responses have been reported in Australia, Hawaii, and Brazil. In Florida, we have observed considerable improvement in the production of Siratro (Macroptilium atropurpureum …
Effect Of Lime On Lucerne In Relation To Soil Acidity Factors,
2026
Department of Agriculture, AU
Effect Of Lime On Lucerne In Relation To Soil Acidity Factors, G P. Mahoney, H R. Jones, J M. Hunter
IGC Proceedings (1977-2023)
Most soils in northeastern Victoria are acid, and problems commonly occur with lucerne (Medicago sativa) establishment and production. Aluminum and manganese have been recognized as major components of soil acidity. Liming to reduce exchangeable aluminum (Al) has been suggested as a rational approach to determining the lime requirements of lucerne growing in acid soils. This study was undertaken to clarify the relationship between soil acidity factors and lucerne growth and to provide a basis for liming recommendations in northeastern Victoria. The aim was: (1) to determine the effect of a range of rates of lime on establishment, production, and …
Some Effects Of Applied Nitrogen On Grass Growth In Field Swards At Different Times Of Year,
2026
University College of Wales
Some Effects Of Applied Nitrogen On Grass Growth In Field Swards At Different Times Of Year, D Wilman, P T. Wright
IGC Proceedings (1977-2023)
Results from 21 field experiments are examined to discover the effects oflevel of applied nitrogen (N) on the regrowth of grass over 8 weeks following a cutting and the situation after about 6 weeks' regrowth, at different times of year. Percentages of N and nitrate Nin herbage generally increased in the early stages of regrowth and then declined. The better the growing conditions were, the faster was the decline. The positive effect of applied Non relative growth rate tended to be greatest and most short-lived when growing conditions were most favorable. Response to applied N increased as growing conditions improved …
Effect Of N-P-K Fertilization On Mineral Composition Of Poa Pratensis L. Grown On A Shallow Muck Soil,
2026
Purdue University
Effect Of N-P-K Fertilization On Mineral Composition Of Poa Pratensis L. Grown On A Shallow Muck Soil, J W. Lightner, C L. Rhykerd, G E. Van Scoyoc, D B. Mengel, C H. Noller, B O. Blair
IGC Proceedings (1977-2023)
More than 1 million ha of muck soil suitable for agriculture exists in the northern portion of the Corn Belt in the U.S.A. Corn (Zea mays L.) and soybeans (Glycine max [L.J Merrill) are the major grain crops grown on these soils. Because of problems associated with producing grain crops (e.g., wet conditions, early frosts, excessive weed competition), many farmers are using these muck soils for pasture. Since very little information is available on the fertility requirements of the pastures, a 2-year study was initiated in the spring of 1979 on Edwards muck soil (Limnic Medisaprist) on the Pinney-Purdue …
Effect Of Converting Chaparral To Grassland On Soil Fertility In A Mediterranean-Type Climate,
2026
University of California
Effect Of Converting Chaparral To Grassland On Soil Fertility In A Mediterranean-Type Climate, M B. Jones, R L. Koenigs, C E. Vaughn, A H. Murphy
IGC Proceedings (1977-2023)
In the region of Mediterranean-type climate in California, brush is converted to grassland to reduce fire hazards, increase feed for herbivores, and increase water yields. There is little information on how this change of cover type affects soil fertility over a long period. Research was initiated to measure the long-term effect of converting brush to grass on the availability of nutrients in the soil. In 1956 chaparral growing on Los Gatos soil (fine-loamy, mixed mesic family of typic argixerolls) was crushed, burned, and seeded to grasses and clovers, and half the area was fenced to exclude herbivores. Sprouting brush either …
Waste- Water Application, Dry-Matter Production, And Nitrogen Balanced Rhodesgrass Grown On Fine-Textured Soil Or On Sand Dunes,
2026
The Volcani Center
Waste- Water Application, Dry-Matter Production, And Nitrogen Balanced Rhodesgrass Grown On Fine-Textured Soil Or On Sand Dunes, T Kipnis, A Feigin, I Vaisman, J Shalhevet
IGC Proceedings (1977-2023)
The shortage of irrigation water in the semiarid zone of Israel necessitates the use of partially treated municipal effiuents for irrigation of forage grasses. Irrigation with sewage effiuents is being considered very carefully with the aim of maximizing production and minimizing the pollution ha.zarc;l. A high nitrogen (N) input originating from intensive application of effiuent water may well increase dry-matter production, but it also increases t,he pollution hazard. Frequent application of relatively small quantities of effiuent water was suggested as an efficient method of improving N uptake by rhodesgrass ( Chloris gayana Kunth.) swards. It was expected that nitrate pollution …
Manurial Value Of Liquid, Anaerobically Digested Sewage Sludge On Grassland In The West Of Scotland,
2026
University of the West of Scotland
Manurial Value Of Liquid, Anaerobically Digested Sewage Sludge On Grassland In The West Of Scotland, K F. Edgar, R D. Harkess, J Frame
IGC Proceedings (1977-2023)
The manurial value of liquid, anaerobically digested sewage sludge is under assessment in west Scotland to evaluate the effects of disposal on grassland. The concentrations of plant nutrients in sludges have been measured with sludge total N being considered as two fractions, volatile N and organic N. The herbage yield response to sludge N, relative to fertilizer N, has been measured in a number of field trials evaluating the effects of sludge composition and season of application. The concentration of organic N, P, and Kin sludge depends on the dry-matter (DM) concentration, which was quite variable (3-100 g/kg). Volatile N …
Availability Of Soil Phosphate To Tropical Pasture Species,
2026
CSIRO
Availability Of Soil Phosphate To Tropical Pasture Species, F W. Smith
IGC Proceedings (1977-2023)
Quantitative measurements of the amount of soil phosphate available to plants were made by an isotopic-dilution technique (L-value). Following very thorough mixing and equilibration of 32P with soil P, sequential harvests of perennial pasture species were used to monitor the available P pools in two alkaline clay soils. In initial experiments with Cenchrus ciliaris (buffelgrass), an apparent increase was noted in the size of the available P pool over a number of sequential harvests during a 3-month period. This finding suggested that P was being transferred from a previously unavailable pool to the available pool during the experimental period. Planting …
Phosphorus Utilization In Grassland Ecosystems,
2026
Ruakura Soil and Plant Research
Phosphorus Utilization In Grassland Ecosystems, J Karlovsky
IGC Proceedings (1977-2023)
The process of phosphorus (P) fixation by soil was long thought to result in large losses of P, an idea that led to a common belief that plants can recover only about 10 % to 25 % of applied P. Because such small recoveries were considered unrealistic and contrary to common farming experience, the efficiency of P utilization in agricultural ecosystems has been investigated. This was done by using (1) a balance sheet approach in long-term P maintenance trials that had reached a steady state, and (2) published data fitted to a common nutrient cycle for nonsteady-state conditions. The efficiency …
Seed Production Potentials Of Eight Tropical Pasture Species In Regions Of Latin America,
2026
CIAT
Seed Production Potentials Of Eight Tropical Pasture Species In Regions Of Latin America, J E. Ferguson, D Thomas, R P. De Andrade, N Souza Costa, S Jutzi
IGC Proceedings (1977-2023)
Early identification of geographic regions providing high and consistent seed yields for species of interest, especially legumes, would be very advantageous. Our objectives were (1) to identify potential seed yield and the principal determinants thereof for a range of species, (2) to determine progressively the relative seed-production potential of distinct geographic regions, and (3) to stimulate emphasis upon seed-production issues within pasture programs. Eight grass and legume species, either promising accessions or local cultivars, were established in replicated pure stands at five locations. Compound fertilizers were applied, including nitrogen for the grasses. Seed was harvested once each time a seed …
