Plant Pathology Commons^™

Effect Of Rate And Placement Of Phosphorus On The Establishment Of Legume-Based Tropical Pastures On Oxisols, J M. Spain, R Gualdron, C Perdomo, P Avila

IGC Proceedings (1977-2023)

The phosphorus (P) requirements of perennial forage plants adapted to tropical savanna ecosystems are low compared to those of most annual crops or unadapted forage species (Andrew and Jones, 1985; CIAT, 1978). Perrenials are capable of accumulating P in the biomass over time and good pasture management favors micro-environmental conditions which can result in the recycling of P almost independent of the mineral soil (Spain and Salinas, 1985). It has been shown for crops that for maximum fertilizer efficiency at low rates, P should be concentrated near the seed to optimize fertility for seedlings, but there are few data for …

Use Of Cattle Slurry For Irrigated Temporary Grasslands, J Tomasik

IGC Proceedings (1977-2023)

Available literary sources deal almost exclusively with the slurry application for semi-natural grassland in diluted form, with varying rations of slurry and water (Rais and Kralovec, 1977, 1978 ; Schechtner, 1978 ; Schechtner, 1980; Sharda et al.,

1977 ; Tuney, 1980), The efficiency, i.e. production effect of slurry compared with industrial fertilizers varies in the quoted cases over the range of 50 to 111 %, depending on the most diversified natural and operating factors. We have therefore undertaken the task of identifying potential production capaci­ties of the selected set of monocultures of grasses in the appli­cation of increasing dosages of …

Influence Of Phosphorus Fertilization On Bahiagrass And Water Quality, G G. Payne, J E. Rechcigl

IGC Proceedings (1977-2023)

Increasing evidence suggests that P concentration is the pri­mary factor controlling the eutrophication of many surface waters (Taylor and Kilmer, 1980). Leaching and runoff losses of soluble P fertilizers applied to beef cattle pastures to increase forage production are believed to be a significant source of this P entering the water. Despite the fact that nearly one million hectares of bahiagrass are grown annually in Florida, relatively little is known about the nutrient requirements of bahiagrass for optimum forage production and quality. Currently, fertil­izer rates of up to 112 kg P2Os/ha are being recommended for bahiagrass pastures. There is mounting …

Potassium And Sulfur Fertilization Effects On Alfalfa Yields And Concentrations Of Minerals And Amino Acids, M Collins

IGC Proceedings (1977-2023)

Alfalfa (Medicago sativa L.) is an important perennial legume in ruminant feeding programs. Mechanical dewatering of alfalfa herbage yields a protein concentrate that contains 8.5 % of the DM and 29 % of the N from the original crop (Collins, 1985). Nonruminants would benefit from an increase in S amino acid concentrations of alfalfa since S amino acids limit utilization of leaf proteins (Byers, 1983). A greenhouse study was conducted to determine the effects ofK and S fertiliz­ation on the yield, composition and amino acid concentrations of alfalfa herbage.

Effects Of Phosphogypsum, Phsophorus And Lime On Andropogon Gayanus Kunth, V T. Paulino, E Malavolta

IGC Proceedings (1977-2023)

There are several factors which determine the low animal productivity in the tropics. Among these factors, inadequate nutrition is the most limiting one followed by the low natural fertility and high acidity of the soils in these regions. Previous findings have shown important soil nutrient deficiencies in some Brazilian cerrado soils. Malavolta (1952) demonstrated sulfur (S) deficiencies, while Werner et al. (1967) found plant response to S. Responses to phosphorus addition are very common in this kind of soil and in tropical America there are rates of phosphorus being applied, which sometimes are uneconomical for the formation and maintenance of …

Red Clover Needs For Mobybdenum And Boron Soil Threshold Values Of Deficiency And Toxicity, H Gembrazewski

IGC Proceedings (1977-2023)

Red clover is a precious and promising fodder crop in Poland. Even on acid soils its yields are satisfying, if sufficient level of exchangeable Ca is present. Symbiotically fixed N covers N needs, but fixing effectiveness and rate of further changing of nitrogen compounds depends on optimal molybdenum supply. It is a component of such enzymes as nitrogenase and nitrate reductase, which make it necessary for Rhizobium as well as clover. However, Mo surplus is toxic for animals (the relation of Mo:Cu is of import­ance). As other leguminous plants, red clover needs much boron. Yield of 15 t of dry …

An Effective P Application Method For Dactylis Glomerata, M Hojito, A Nishimune, M Noshiro

IGC Proceedings (1977-2023)

There are two practical ways to apply phosphorus (P) fertil­izer on cutting type grasslands in Hokkaido, Japan. The first one is to apply P at a rate of about I 00 kg P2Os/ha in the spring (April) in one application. Some reasons for this method have been explained (Hayakawa et al., 1951). However, in some cases, it is more convenient for practical management to apply three equal amounts of P, at three different times during the year (April, June and August) the same as other fertilizers such as nitrogen or potassium. That is a second way. Grassland soil is acidified …

Distribution Of Phosphorus And Aluminum In Acidic Pasture Soils And Effects On Growth Of Subterranean Clover, M J. Mclaughlin, T R. James

IGC Proceedings (1977-2023)

In south-eastern Australia, pasture improvement and the use of superphosphate fertilizers have resulted in the gradual acidi­fication of many soils under subterranean clover pastures (Wil­liams, 1980). Despite high values of exchangeable and extract­able aluminium (and low pH) recorded in many soils, there are few reports of significant responses of clover growth to lime application in the field. In this study we examined the vertical distribution of CaCb-extractable aluminium (Al) and available phosphorus (Bray P) in pasture topsoils. We also simulated the conditions in the field sites by investigating in solution culture the response of subterranean clover to various concentrations of …

Relations Entre Facteur Hydrique, Drainage Er Evolution De La Flore Des Prairies En Lorraine, S Oberle, S Plantureux, R Bonischot, A Guckert

IGC Proceedings (1977-2023)

Une part non negligeable (plus de 50 %) des Surfaces Agri­coles lorraines est occupee par des prairies permanentes. Or, nombre de ces dernieres souffrent d'exces d'eau qui limitent gravement leur productivite. Le developpement recent d'opera­tion de drainage offre la possibilite de lever un facteur limitant et, ce faisant, d'augmenter significativement la qualite et la quantite du fourrage produit. Il convient toutefois de rappeler que Jes prairies permanentes sont constituees d'un ensemble d'especes vegetales en equilibre avec leur milieu ecologique. la perturbation de ce dernier, en !'occurrence la modification du regime hydrique, va entrainer la mise en place progressive d'un nouvel …

Influence Of Sulfur And Nitrogen On Bahiagrass, J E. Rechcigl, G G. Payne, R J. Stephenson

IGC Proceedings (1977-2023)

One of the most important forage crops grown in Florida is bahiagrass, with nearly 1 million ha grown annually. Bahia­grass is found on more acres than all other improved grass pastures combined. Average annual dry matter yields for bahiagrass range from 9 - 16 t/ha. Bahiagrass is adapted to most climatic conditions throughout the state and can be grown on upland well drained sands as well as poorly drained « flatwoods » soils. Until recently, little attention has been focused on the need for S fertilization for plant growth. This is understandable since, in the past fertilizers were contaminated with …

The Depletion Of Soil K As Affected By Fertilization Of Eragrostis Curvula Used For Hay Production, N.F G. Rethman, C C. De Witt

IGC Proceedings (1977-2023)

Eragrostis curvula is widely planted as a hay crop in the summer rainfall areas of South Africa. For many years the main yield determinants have been regarded as N and P. As a result of the depleting effect of crop removal low K status is becoming more common. The beneficial effect of K fertiliz­ation, in combination with N, has been illustrated by Miles et al. (1986) and Rethman and De Witt (1839). Information on the rate of build up and/or depletion of soil K under different fertilization regimes is, however, required to facilitate the plan­ning of fertilization strategies. The monitoring …

Studies On The Macropores Structure Of Grassland's Soil, K Sato, K Tokunaga

IGC Proceedings (1977-2023)

The purpose of this study is to examine the structure of macroporous soils which allows better aeration, water reten­tion and drainage. Previous investigations of macroporous soils have dealt with drainage (McIntyre and Sleeman, 1982), void forms (Tippkotter, 1983; Walker and Trudgill, 1983) and X-ray radiography (Rogaar, H. and R.A.H. Thiadens, 1975). Analyses of these studies have not proved sucessful to explain the effect of the soil structure as regards water retention and drainage. Therefore, the present study was designed to deter­mine the structure of macroporous soils by use of soft X-ray radiography and soil physical properties. Tokunaga et al.,(1984, 1986, …

Study Of Some Factors That Influence Upon P Fertilization On Pastures From Red Ferralitic Soil, Marta Hernandez, A R. Mesa

IGC Proceedings (1977-2023)

The importance of P for vegetal nutrition has been a topic of study for several workers. However, results obtained have not always been positive using P fertilizer due to some factors such as the content of this nutrient in the soil and its fixation capacity. This study was conducted in order to evaluate the response of guinea grass cv. Likoni and buffel grass cv. Biloela to P fertil­ization. These pastures were selected due to their favourable behaviour and the different levels of exigency to P that they pre­sent.

An International Perspective Of Dairying In New Zealand, M Murphy

IGC Proceedings (1977-2023)

It is often said that the New Zealand dairy industry is the most low­cost efficient industry of the main dairy industries world wide. I am certainly not going to put a case against the New Zealand dairy industry today but I am going to look at it from a slightly different perspective to Ireland. Is the industry low cost, efficient? How do you measure that? I nm going to give a personal view on some of the strengths and weaknesses. I am going to suggest that there are some surprising weaknesses in an otherwise extremely efficient industry and I am …

Factors Influencing The Availability Of Soil Cobalt And Its Uptake By Herbage, J E. Paterson, D A. Klessa, A Macpherson

IGC Proceedings (1977-2023)

Severe cobalt (Co) deficiency is now rare in Scotland but subclinical deficiency, although difficult to diagnose, is com­monly thought to be reducing the profitability of many sheep and beef farms (COSAC/SARI, 1982). By understanding the factors which determine herbage Co content and Co availablity to ruminants, areas at risk may be predicted and preventative measures taken. To this end, a series of field and laboratory experiments were investigated:

Co adsorption and desorption characteristic of soils. Effects of fertiliser N on herbage Co content. Response of pasture and grazing ruminants to applied Co fertiliser.

Variations Saisonnieres De La Croissance D'Une Prairie De Setaria Anceps En Guadeloupe, P Cruz, O Sobesky

IGC Proceedings (1977-2023)

La production des cultures fourrageres en zones tropicales est frequemment modifiee par des effets saisonniers. Le deficit hydrique, la photoperiode et la temperature peuvent etre a l'origine de ces variations mais seulement le premier facteur peut etre controle a l'echelle d'une parcelle. L'effet de la photo­periode est bien connu sur des plantes stoloniferes comme le Pangola, lequel reduit fortement sa croissance pendant la saison de jours courts (Salette, 1971; Cruz et al., 1989). Parmi certaines plantes a talles (Crespo, 1986) des variations plus fai­bles sont rapportees mais sans faire la part de l'effet des basses temperatures. L'objectif de ce travail …

Relationships Between Root Morphology And Nutrient Uptake In Winter-Flooded Mediterranean Grasslands, A J. Hernandez, J Pastor

IGC Proceedings (1977-2023)

One of the functions of roots directly related to the environ­ment is that of uptake. However, since legume are worse competitors than grasses for nutrients and water, root mor­phology may be an important factor in this competition in grassland systems. This has been very interesting for the study of the dynamics of flooded pastures in West-Central Spain. Their main root characteristics were studied in a previous paper (Hernandez and Pastor, 1988). Now we intend to approach the knowledge of the relationships between root morphology and nutrient uptake.

Effect Of Soil Moisture On The Growth And Development Of Seedlings Of Some Grass Species, J Jargiello, Wanda Harkot

IGC Proceedings (1977-2023)

Soil moisture in the upper layer is one of the fundamental factors favouring successful grass seeding. In our country, especially difficult conditions of germination and growth of seedlings can be observed on muck-peat soils, particularly on those of degraded, easily drying muck (Kowalczyk and Okruszko, 1973). Studies ofRoguska-Wasilewska (1960) point out that the grass ventilation system is not the same in all the species, which differentiates their resistance to soil overdrying. The aim of the studies was to determine the effect of muck­peat soil moisture in its upper layer on some morphological features of seedlings of some grass species and …

The Above Ground And Root Production Of Grass On Different Soils, Sophia Toth

IGC Proceedings (1977-2023)

The total DM production of grass involves the above ground and root yields. The special literature mainly focuses on utiliza­ble grass yields while details of root production are less avail­able. The latter data show that grass annually produces large amounts of root improving the soil characteristics thereby. Very few results are available of the DM yield of grass on different soils under uniform ecological conditions. In Hungary soils under grass show a fairly diversified pic­ture, ranging from sands to heavy clay soils (solonchak, solonetz). In our experiment we investigated the effects of different soils and fertilization on the total DM …

Response Of Forage Oats To Nitrogen Fertilizer In High And Low Fertility Soils, N Moreira

IGC Proceedings (1977-2023)

Forage oats are used extensively as whole-crop in rainfed areas of Portugal as is traditional in Mediterranean areas. They are cropped with minimum inputs, and increasingly in mixtures with annual legumes such as Vivia sativa (Moreira, 1989). In addition to the fact that relatively low yields are obtained in these conditions, the oats harvested during grain filling have a very low crude protein content, which severely limits their nutritive value (Eagles et al., 1979; Abreu et al., 1982). The aim of the present study is to determine the effects of nitrogen fertilizer on whole-crop forage oats in terms of dry­matter …