Agronomy and Crop Sciences Commons^™

Varying Phosphorus Fertilization With Pasture Type And Longevity, W F. Wedin, A P. Mallarino, M S. Gregory, C P. West, R D. Voss

IGC Proceedings (1977-2023)

We conducted studies which assessed soil phosphorus (P) status and responses to P fertilization in five pasture types of varying longevity. The main objective was to determine if current recommendations for P fertilizer on pastures, as based on P fertilization response studies in ungrazed small-plot studies, are suitable. In two of the five pasture types, soil P was at levels such that yield response from applied P was insignificant. Plant tissue P concentration was increased but was not a good indicator of P fertility needs. Soil P was both concentrated in areas of the pasture extending to 30 m from …

Some Ecological Features Of Phosphate - Solubilizing Microorganisms In Grassland Soil, M Nishio

IGC Proceedings (1977-2023)

Phosphate-solubilizing (PS) microorganisms made up ca. 1 % of bacterial (including actinomycetous) and ca. 10% of fungal populations of grassland soils. They were speculated to solubilize bound phosphates in the non-rhizosphere soil in the presence of a large amount of available carbon sources by the following results; 1) plate counts of PS bacteria and fungi greatly increased on the agar plate rich in carbon source, 2) the numbers of PS bacteria and fungi significantly increased in proportion to the content of total carbon and not to that of total or available phosphorus in soil, 3) the soil applied with a …

Effect Of Anhydrous Ammonia (Nh3) And Nitrifying Inhibitor On Productivity Of Grass Pastures, V G. Iglovikov, V A. Kulakov, G V. Blagoveshchensky

IGC Proceedings (1977-2023)

Investigations on the effect of anhydrous ammonia and nitrifying inhibitor on qualitative and quantitative indices of stand formation have been carried out during 4 years in the irrigated pasture with grass stand established on the drylands with sod-podzolic soils. The positive effect of anhydrous ammonia on pasture productivity had been determined: on an average for 4 years dry matter yield increased compared to PK by 1.6 times and protein - by 2.2 times. When applying anhydrous ammonia together with nitrifying inhibitor dry matter yield increased by 1.9 times compared to PK by 16 % relative to NH3PK, protein - by …

Effects Of Interactions Between Temperate And Phosphorus Supply On Growth And Critical Phosphorus Concentrations In Macroptilium Atropurureum Cv. Siratro, F W. Smith, C S. Andrew

IGC Proceedings (1977-2023)

Effects of interactions between aerial temperature, root temperature, and phosphorus (P) supply on growth and critical P concentrations in the tropical legume Mecroptilium atropurpureum cv. Siratro have been studied in controlled environ­ments. Maximum growth of siratro when supplied with adequate P was achieved at aerial temperatures of 30/25°C ( day/night) and 35/30°C when root temperatures were maintained at 30°C. Aerial temperatures of 25/20 °C severely restricted growth, particularly when a root temperature of 20°C was used. Neither aerial temperatures nor root temperatures had any discernible effect on the amount of P needed to be applied to obtain maximum yield. …

Phosphorus Requirement For Grass Establishment In Five Tropical Soils, M C. Rego, J A. Gomide, R F. Novais

IGC Proceedings (1977-2023)

Phosphorus (P) requirement of 4 grasses grown in 5 tropical soils was studied, in a pot trial. Each soil was screened, limed, fertilized with nitrogen, potassium, magnesium, sulphur and microelements. Five P does - 0, 50,100,200 and 278 ppm -were added to each soil. Guineagrass (Panicum maximum), Jaraguagrass (Hyparrhenia rufa), Buffelgrass ( Cenchrus ciliaris) and Molassesgras (Melinis minutiflora) were grown in each soil. Response to P varied from soil to soil and from grass to grass. Atthe O ppm P dose Guineagrass showed poor establishment in 3 of the soils Molassesgrass established reasonably …

Preliminary Fertilizer Requirement Studies For Legume Based Pasture In Mid-Altitude Zone, Central Yunnan Province, Wang Jinjing, J R. Bruce-Smith, Li Jixin, Wang Mingliang

IGC Proceedings (1977-2023)

There are large areas of hilly land swathed in poor native pasture in Yunnan. While not suited for intensive cropping, the mid altitude areas (1500-3000m) seem ideally suited for development into legume based permanent pastures capable of supporting a substantial grazing industry. The objective of a joint Chinese -Australian project is to find suitable pasture species and define their fertilizer requirements at selected sites within the Province. The field and glass house experiments described here demonstrate there is a need for phosphorous and possibly lime as an essential part of successful legume establishment. There is also an additional requirement for …

Growth And Minerals Of Wild Soybean And Their Relations To Soil, H Park, S N. Hur, U J. Kim

IGC Proceedings (1977-2023)

In order to elucidate plant-soil relationship in natural habitat of wild soybean ( Glycine soja) dry matter yield, number and weight of root nodule mineral content at flowering stage, seed yield and its component, seed protein content and soil chemical characterstics were investigated. Dry matter yield per plant showed significant positive correlation with seed yield and no. of branch per plant. Seed yield greatly depended its components expects no. of seed per pod. Dry matter yield had significant positive correlation with P and pH of soil, K,P and N in plant, and negative with Mg in plant. Seed yield …

Studies On Nitrogen Fixation Of Forage Grasses In Taiwan, K C. Lee

IGC Proceedings (1977-2023)

Experiments were conducted to determine the nitrogen(N)-fixing activities of the tropical forage grasses in Taiwan, the relationship between N-fixing activity and soil fertility and the morphological and the physiological properties of the associated bacteria. Hybrid napier grass (Pennisetum americanum X P. purpureum) cv.A7005 was the most effective in N fixation among 13 species of forage grasses,with 97 nmoles C2H4 per gram dry roots per hour. A negative correlation was found between N activity and total N content in soil. However, no relationship was observed between N-fixing activity and pH value, organic matter, and available P and K in …

Studies On Leucaena-Rhizobium Symbiosis On Northeast Thailand, J Homchan

IGC Proceedings (1977-2023)

A few studies on the symbiosis between Rhizobium and Leucaena leucocephala under soil and environmental conditions of Northeast Thailand are presented. The results obtained so far indicated that the response of high yielding introduced cultivars of L.leucocephala varied with the sources of inoculant used. The finding that some local Rhizobium isolates showed superior symbiotic performance compared with the introduced recommended strain implies that local strains may be of great potential especially for local use. Further study on the ecology of leucaena rhizobia will be useful in an attempt to increase the herbage yield of L.leucocephala through biological nitrogen fixation.

A Tentative For Appreciation Of The Nitrogen Nutrition Status In Grasses- Red Clover Mixtures Compared To Pure Stands, Noelle Amarger, A Mariotti, J Picard

IGC Proceedings (1977-2023)

In our country it is commonly accepted at the level of extension services that growing forage grasses and legumes mixtures can offer to the farmers a good opportunity to achieve high dry matter yield and good quality feed at a lower rate of input than growing pure grass stands. This is supposed to be so due to combination of the chief advan­tages coming from each component as far as their chemical composition and feeding value, the influence of their root system on soil structure, their mineral nutrition character­istics, ... are concerned. A number of experiments have been done, the results …

Effect Of Early Season Nitrogen On Nitrogen Fixation In A Ryegrass/ White Clover Pasture, P M. Murphy, P. Roger Ball

IGC Proceedings (1977-2023)

The effect of rate and time of nitrogen fertilizer application on nitrogen fixation by white clover (Trifolium repens) in a ryegrass sward was studied under field conditions in two consecutive years. Very different weather conditions prevailed over the two years resulting in contrasting seasonal patterns of nitrogen fixation. In 1983 only 30% of the total annual fixation rate was achieved by rate June and this pattern was reversed in 1984. Nitrogen fertilizer affected nitrogen fixation more than clover growth in 1983 but in 1984 a combination of fertilizer and drought reduced both clover growth and nitrogen fixation. At the highest …

Competition Effects On Nitrogen Fixation And Mineral N Uptake In Trifolium Repens L.- Lolium Perenne L. Associations, C P. West, K W. Steele, E A. Halligan

IGC Proceedings (1977-2023)

Improved While clover (Trifolium re pens L.) cul ti vars can potentially increase the input of nitrogen (N) from symbiotic fixation into clover-grass pastures and maintain elevated N2 fixation rates in the presence of nitrogenous fertilizers. The objective of this study was to determine the effects of interspecific competition on N2 fixation and mineral N uptake in white cover-perennial ryegrass (Lolium perenne L.) associations with either a medium-small ('Grasslands Huia') or large leaved ('G18') cultivar. The clover and grass were grown in a controlled environment room in pots that were partitioned to allow either no interspecific competition for shoots and …

Interspecific Differences In Sodium Nutrition Among Tropical Grasses, T Ando, Y Masaoka, K Matsumoto

IGC Proceedings (1977-2023)

In order to clarify interspecific differences in sodium (Na) accumulation and requirement, the following grasses were grown in the nutrient solution with 0-40 ppm Na for 4 weeks; Panicum coloratum (Coloured guineagrass: abbr. as CG, Kabulabula grass: KB and Makarikari grass: MK), P.maximum (green panic: GP and Guineagrass: GG), P. dichotomiflorum (fall panic: FP), Chloris gayana (Rhodes grass: RG), Echinochloa care-galli (Jananese millet: JM), Eleusine coracana ( African millet: AM) and Sorghum vulgare (Sorghum: SG). The ability to accumulate Na in shoots was ranked in the following order; KB and RG: high, GP and MK: intermediate, CG, GG, JM, …

Effect Of The K Fertilization On The N-Mineralization In A Grassland Soil And On The N-Uptake By Italian Ryegrass, I Campino

IGC Proceedings (1977-2023)

In a pot experiment with a hydromorph grassland soil enriched with organic matter containing tagged N and sown with Italian ryegrass N-mineralization and uptake with increasmg K fertilization were investigated. The N-mineralization and the mtnficatlon were promoted with increasing K fertilization. Because the K content of the plant was high enough to guarantee a healthy growth, the higher N uptake, a��d especi��lly the m��reased uptake of mineralized N from the + added organic matter, was attnbuted to the higher content of mmeral N m the sod and to a synergic interaction between K and NO3

Effect Of Invertebrates On Nitrogen Fixation In Temperate Pastures, K W. Steele, R N. Watson, P M. Bonish, R A. Littler, G W. Yeates

IGC Proceedings (1977-2023)

Annual nitrogen fixation in New Zealand pastures is well below its potential. The research reported is part of a programme directed towards identifying limitations to nitrogen fixation by the Trifolium repens-Rhizobium trifolii symbiosis. Sixteen field trials were conducted with tretments designed to provide selective control of various invertebrate pests of Trifolium repens. Measurements included herbage production, botanical composition, nitrogen fixation and root dissections. Application of pesticides significantly increased legume production, the number of nodules/g of Trifolium repens root and nitrogen fixation. Total N uptake in pasture herbage was increased by up to 118 kg N/ha/yr. The increase in nitrogen fixation …

Study Of Nitrogen Transfer From Alfalfa To Associated Timothy Under Field Conditions, M A. Faris, T C. Ta

IGC Proceedings (1977-2023)

In a forage cropping system (legume-grass), some of the nitrogen (N) which is fixed symbiotically by legumes is used by the associated grass. However, very few measurements of such transfer have been conducted under field conditions. The objective of this work was to estimate N transfer from alfalfa to associated timothy under field conditions, by using the 15N dilution technique. There was no significant difference in total N (T-N) content in timothy grown alone or in mixture at cut one. However, the effects of associated alfalfa became apparent at cuts two and three where T-N% increased by 15 to 38% …

The Fate Of Fertilizer Nitrogen Applied To Grass Sward In Japan- Influence Of Sward Age And Season Of The Year, T Kimura, K Kurashima

IGC Proceedings (1977-2023)

The seasonal uEtake of fertilizer nitrogen (N) and the annual fertilizer-N balance in cut orchard grass swards were studied by using the field SN-tracer method under humid temperate condition in Japan. 1) Fertilizer-N applied in early spring (for the first cut) and early summer (for the third cut) was readily absorbed by grass, but N applied in autumn (for the fifth cut) was slowly absorbed, the fact is considered to reflect on the efficiency of fertilizer-N. Much more fertilizer-N was recovered in grass (the total of top and root) of the first and third cut than in grass of the …

Maintenance Of Lolium Perenne L. In Mixture, K Sato, R Meguro, T Nomoto, M Nashiki

IGC Proceedings (1977-2023)

Lolium perenne L. (PRG) is one of the promising species in the northern Japan. However, this species is utilized less widely due to short persistency. The study was conducted to clarify the proper conditions for maintenance of this species in the context of defoliation treatments. The grasslands mixed with Dactylis glomerata L. (OG), Festuca arundinacea Schreb. (TF), Poa pratensis L. (KBG) and PRG were established and botanical composition of this mixture were measured in terms of Summed Dominance Ratio (SDR) under grazing (3 Japanese Black Cattle per ha) and cutting (3 times a year) conditions. PRG were maintained well …

Growth Analysis In The Regrowth Of Italian Ryegrass As Affected By Fertilization Level, K Watanabe, Y Sato, H Shirakawa, S Abe

IGC Proceedings (1977-2023)

Growth analysis was conducted to clarify the process of the regrowth, and the relation between LAI and plant height, percentage light penetration, CGR or NAR in the 2nd crops of Italian ryegrass (Lolium multiflorum) given 3 rates of fertilizer (20kg N + 10kg P205 + 17.5kg K20 ha-1, twice and 4 times). For the analysis, cubic regrassion curves were used, as they were fitted significantly by the changes of plant height, LAI, percentage light penetration and dry weight of whole plant with the regrowth. CGR (dt/dw) was obtained by the differentiation of cubic regression equation in the dry weight (w); …

Conditions For Raising The Yield Of Orchardgrass, S Kawashima

IGC Proceedings (1977-2023)

Up to the present, studies have been done on cutting height and plant length at the time of cutting. Concern with planting density, on the other hand, has been slight, with the result that reports which consider all three factors are almost non existent. Our field experiment considered these three aspects to determine the conditions for raising the yield of orchardgrass. Our perspective in the research was ecological.

The following points were recognized:

1) Long plants at cutting time are preferable to short ones.

2) Planting density should be high rather than low.

3) Cutting height must be low.