Forage quality and yield increments of intensive managed grassland in response to combined sulphur-nitrogen fertilization Dedicated to Prof. em.Dr. Alois Kornher on his 75th birthday.

Abstract

A three-year experiment was carried out at three different sites in northern Germany to investigate the effects of combined sulphur (S, up to 50 kg S ha^?1 year^?1) and nitrogen (N, up to 300 kg N ha^?1 year^?1) fertilization on dry matter (DM) yield and forage quality. There was an interaction effect of site, year, S and N fertilization. The greatest DM yield increment relative to yield at the start of the experiment (1997) with no S and N applied was 10.2 t DM ha^?1 at Ostenfeld (arable grassland). Cattle slurry when applied to provide 50 kg N ha^?1 and 10 kg S ha^?1 did not noticeably increase yield. The S content in forage decreased significantly over the years without S fertilization. At 300 kg N ha^?1 and 0 kg S ha^?1, crude protein (CP) contents achieved 173 g kg^?1 DM and were diluted due to higher DM yields with S fertilization. The true protein content (TP% of CP) differed significantly at 300 kg N ha^?1. TP achieved 93% with 50 and 87% with 0 kg S ha^?1 year^?1, respectively. In conclusion, with N fertilizer intensities in the range of 300 kg N ha^?1, it is necessary to apply 25 kg S ha^?1 to improve forage yield and quality. On the other hand, with N fertilization levels below 300 kg N ha^?1, S fertilization could be omitted.     

Derivation of diagnostic indices for assessing the sulphur status of Panicum maximum var. trichoglume

Abstract

The effects of nitrogen fertilization and age of regrowth on a number of indices for assessing the sulphur status of the perennial tropical pasture grass Panicum maximum var. trichoglume (green panic) have been examined in pot experiments. A non‐rectangular hyperbola regression model has been used as an aid in deriving critical sulphur concentrations and evaluating their confidence limits. The merits and limitations of this model together with problems associated with other methods of deriving critical nutrient concentrations are discussed.

Results indicate that critical total S concentrations in whole plant tops declined markedly with age of regrowth. Critical sulphate S concentrations were more stable with age of regrowth, concentrations in excess of 0.012% being indicative of adequate sulphur for maximum plant yield. It is also suggested that plants have adequate sulphur when more than 12% of their total S content is in the sulphate form. N:S ratios may provide a useful guide for assessing sulphur status but should be treated with caution when the nitrogen supply to the plants is high.     

Nitrogen application effects on forage sorghum production and nitrate concentration

Abstract

Forage sorghum (Sorghum bicolor (L.) Moench) is an important annual forage crop but prone to high nitrate concentration which can cause toxicity when fed to cattle (Bos taurus and Bos indicus). Two field experiments were conducted over six site-years across Kansas to determine the optimum nitrogen (N) rate for no-till forage sorghum dry matter (DM) yield and investigate the effect of N fertilization on sorghum forage nitrate content. A quadratic model described the relationship between sorghum DM and N rate across the combined site-years. Maximum DM yield of 6530?kg ha^?1 was produced with N application rate of 100?kg N ha^?1. The economic optimum N rate ranged from 55 to 70?kg N ha^?1 depending on sorghum hay price and N fertilizer costs. Crude protein concentration increased with N fertilizer application but N rates beyond 70?kg N ha^?1 resulted in forage nitrate concentrations greater than safe limit of 3000?mg kg^?1. Nitrogen uptake increased with N fertilizer application but nitrogen use efficiency and N recovery decreased with increasing N fertilizer rates. In conclusion, forage sorghum required 55–70?kg N ha^?1 to produce an economic optimum DM yields with safe nitrate concentration.     

Variations in nitrogen uptake and nitrate-nitrogen concentration among sorghum groups

Nitrogen uptake and nitrate-N concentration in forage sorghums, which are related to ground water pollution or feed quality under conditions of crop fertilization by only animal wastes, were examined. Seventy-four genotypes of sorghum and Sudan grass were tested. They were classified into 4 groups; grain type and dual purpose type sorghums (6 and 13 genotypes, respectively, Sorghum bicolor Moench), sorgo type sorghum (21, S. bicolor), Sudan type sorghum (22, S. bicolor × S. sudanense (Piper) Stapf), Sudan grass (12, S. sudanense). There was a strong correlation between dry matter (DM) yield and N uptake, with the sorgo type producing the highest DM matter yield and showing the highest N uptake. Nitrate-N, which causes nitrate poisoning of ruminants, was detected mostly in the stem of all the genotypes. The nitrate-N concentration based on DM could be calculated accurately by multiplying the nitrate-N concentration of stem on a fresh matter basis by the DM partitioning ratio of stem divided by the DM concentration of stem. The grain type and the dual purpose type of sorghums with dry stem showed the lowest nitrate-N concentration because these plants had a lower DM partitioning ratio of stem and higher DM concentration of stem. Sudan grass and Sudan type sorghum with the genetic background of Sudan grass showed higher nitrate-N concentrations owing to their ability to accumulate nitrate-N.     

Alfalfa/grass response to nitrogen and phosphorus applications

Abstract

Alfalfa/grass (Medicago sativa/Dactylis glomerata, Bromus) yield and quality responses to nitrogen (N) and phosphorus (P) fertilizer applications are well documented. The magnitude of the P response and in turn N, may however, be limited by the relative immobility of P in the soil. A two‐year field study was conducted to determine the response of an established alfalfa/grass stand to combinations of a one‐time broadcast application of N, P, and sulfur (S) rates with fall or spring applications of P. Nitrogen and P applications increased forage production, nutrient concentration and nutrient content, particularly in the first production year. No S response was observed. Fall P applications were superior to spring applications only in the first year of production. If annual broadcast applications of P are made to existing alfalfa/grass stands in Intermountain areas, fall applications are recommended.     

Sulfur fertilization of wheat and triticale for forage production

Abstract

Throughout the Great Plains, wheat (Triticurn aestivum L.) is utilized for grain and forage production. Triticale (Triticum aestivum L. x Secale cereale L.) is known for its ability to produce large quantities of high quality forage. With recent improvement in winter hardiness, interest in and acreage of triticale is spreading north in the central Great Plains. The forage production potential of wheat and triticale is essential to many livestock producers. Very few data are available concerning the effects of sulfur (S) fertilization on production and quality of wheat or triticale forage. Greenhouse research was conducted to evaluate the addition of S as either ammonium thiosulfate (ATS) or ammonium sulfate (AS) on production and quality of wheat and triticale forage on four different soils. Sulfur fertilization increased forage yields and S concentrations of both crops on all soils, and in many cases, resulted in higher N concentrations in the forage. Sulfur fertilization also increased in vitro digestibility of wheat, but had little effect on triticale digestibility. Both S sources performed similarly. Application of S after the first clipping was effective in increasing second clipping forage production on three of the four soils, and forage S concentrations were dramatically increased for both crops on all soils. Although the magnitude of response varied, S fertilization was effective in increasing production and quality of wheat and triticale forage grown in the greenhouse.     

The productivity and energy potential of alfalfa,fodder galega and maize plants under the conditions of the nemoral zone

This study aimed to investigate the productivity of two C3 legumes – alfalfa (Medicago sativa L.) and fodder galega (Galega orientalis Lam.) – and the feasibility of their use as renewable energy resources. Maize (Zea mays L.), a well-established bioenergy crop belonging to the C4 plant group, was used as a baseline in comparison. Field trials were conducted at the Institute of Agriculture at the Lithuanian Research Centre for Agriculture and Forestry during the period 2012–2013. The perennial forage legumes were grown without mineral or organic fertilizers. The maize was grown (a) without and (b) with nitrogen fertilizers. The perennial forage legumes were harvested three times per growing season. Carbon (C), nitrogen (N) and sulphur (S) contents of biomass were determined by using a dry combustion method. The calorific value of biomass was determined by a combustion method using an IKA bomb calorimeter. The largest share of the total annual yield of biomass of perennial forage legumes was obtained from the first cut and amounted to 54% and 57% for alfalfa and fodder galega, respectively. The S content of biomass was similar in all crops investigated, but the N content was higher in perennial forage legumes. Biomass C content did not differ between the crops, but the C:N ratio was widely varied – from 28–35 in fertilized maize, to 16–17 in alfalfa and 15–16 in fodder galega. This study showed that alfalfa and fodder galega can be grown as energy crops under less intensive management; however, the specific chemical composition of biomass should be considered before choosing the most appropriate conversion process.     

Sulphur Mineralization and Carbon,Nitrogen, and Sulphur Relationships in Some Alfisols of India

Abstract

The amount of sulphur (S), nitrogen (N), and organic carbon (C) in different layers of soils from some Alfisols varied considerably with location. The amount of S extracted by different extractants as a percentage of the total S was in the order of organic (3.5%)>0.05 (N) NH₄OAc+0.25 (N) HOAc (1.9%)>0.1 (N) H₃PO₄ (1.8%)>0.025 (N) CaCl₂ (1.8%)>0.03 (N) NaH₂PO₄ (1.7%)>0.001 (N) HCl (0.6%). In all the soil series SO₄ ^2?‐S mineralization decreased up to the second week after incubation, followed by a slight increase up to the fourth week, a subsequent decline up to the sixth week, and a slight increase up to the eighth week. The C:N, C:S, N:S, and C:N:S ratios averaged 9.4:1, 63.7:1, 6.9:1, and 94:10:2.08, respectively.     

The effect of time of S application on yield and sulphur uptake of canola

Abstract

Little information was available on the yield response of canola species to application of sulphur (S) fertilizer at various times after seeding. Split plot experiments having two cultivars, ‘Candle’ (Brassica campestris L.) and ‘Regent’ (Brassica napus L.) as main plots and four times of applying S fertilizer as subplots after seeding (0, 14, 28 and 42 days) were set out on six sulphur deficient soil sites of northern Saskatchewan. Sodium sulphate fertilizer was applied at 25 kg S/ha and all plots received 100, 20 and 50 kg/ha of N, P and K, respectively. The cultivar ‘Regent’ yielded 1.24 t/ha which was significantly higher than ‘Candle’ yielding 0.98 t/ha (average over sites). An estimated linear reduction in yield of canola grain of 0.11 t/ha for ‘Candle’ and 0.40 t/ha for ‘Regent’ was obtained with S applied at 42 days after seeding date. This difference in response to time of S application resulted in a cultivar x time of S interaction. On two other sites testing high in S (above 40 kg S/ha) there was an apparent increase in grain yield with S application at the rosette stage and at the second application time (12 days before reseeding because of frost damage). Sulphur uptake in grain and straw was highly correlated with yield of grain and straw. Average uptake of S in straw (15.1 kg S/ha) was higher than in grain (4.4 kg S/ha). With few exceptions, yield and S uptake in grain and straw was less with S fertilizer applied at late stages of growth than at seeding.     

Effect of nitrogen and sulphur fertilization on the yield and composition of winter oilseed rape

Abstract

A field experiment was conducted to assess the effects of varying levels of sulphur (S) and nitrogen (N) supply on oilseed rape (Brassica napus L. var. Rafal) grown in a soil assessed to be in the low category for plant available sulphate (SO₄). There were no significant effects on crop yield as a result of applied S for any of the treatments. This was probably due to a significant input of atmospheric S as a result of the wetter than average year. However, there were significant compositional effects on total S, total N and sulphate‐sulphur (SO₄‐S) which has implications for the supply of S from soil which can often display a range of S availabilities. Effects on composition were most marked as the crop reached maturity.     

Ryegrass forage yield and quality response to sulfur and nitrogen fertilizer on coastal plain soil

Abstract

Sulfur (S) deficiency has been reported in some upland soils of the southern United States and S application has improved forage quality on the low‐S soils. A field experiment was conducted for three years to determine ryegrass (Lolium multiflorum L.) dry matter yield and forage quality response to S fertilization. Prilled elemental S was applied each year at two rates (0 and 45 kg S/ha) in combinations with three rates of nitrogen (N) (168, 224, and 280 kg/ha). Wet depositions of S in rain were monitored over the seasons. Sulfur fertilization generally did not increase seasonal dry matter yield and plant uptake of S. Nitrogen application generally increased dry matter yield and protein content during the season. Averaged over the three‐year period, however, forage yield and S uptake increased from 7.7 to 10.5 Mg/ha and 13.9 to 18.8 kg/ha, respectively, as N fertilization increased from the lowest to highest treatment rates. Forage dry matter for each harvest ranged from 0.6 to 2.2 Mg/ha, while S, protein, in vitro dry matter digestibility (TVDMD), and N/S ratio tended to decline seasonally from 2.5 to 1.8, 266 to 142, and 795 to 716 g/kg, and 17.8 to 11.9, respectively. Sulfur input from rainfall was small with a three‐year average of 5.8 kg/ha (±0.64 SE). In some locations of the southern United States, S may not be limiting even when applying high rates of N to high‐yielding forages which annually remove large quantities of S. Because of the lack of yield response from S application and low inputs of S from wet deposition, S from sources other than rainfall may have been considerable.     

Initial and residual utilization by alfalfa and bromegrass of sulphur from 35S‐labelled gypsum

Abstract

An experiment designed to measure the utilization of sulphur from gypsum by forage species and to determine the residual effect in the year following application failed to show a dry matter yield response to S. From 15 to 57% of the total S in the herbage, however, was obtained from the surface application; the proportion was lower in the legume than in the grass, was increased by increasing the rate of gypsum application, was increased by N fertilization of the grass but not the legume and was generally higher in the first two harvests than in the third. 9.4 to 27.4% of the applied S was recovered by three harvests in the first year, the recovery decreasing with increasing rate of application and increasing with N fertilization. Only 1.1% was recovered by the first harvest of the second year when 2.5 to 15% of the S in the herbage was derived from the previous season's application. Evidence of significant downward movement of S in the soil profile is presented to account in part for the low residual effect of gypsum.     

Effect of nitrogen and sulphur fertilizers and seed inoculation with rhizobium phaseoli on the nitrogen‐sulphur relationships of bean (phaseolus vulgaris L.)

A greenhouse experiment with beans (Phaseolus vulgaris L.) was performed in order to investigate the effect of nitrogen and sulphur application and seed inoculation on the yield, leaf area, distribution of different nitrogen and sulphur fractions and N/S ratio in shoot, fruit and root.

Inoculation of plants together with nitrogen or sulphur application produces an increase in the concentration of total nitrogen and a decrease in the accumulation of nitrate‐nitrogen and sulphate‐sulphur in shoot, fruit and root. Leaf area increased more with nitrogen than with sulphur application while the highest amounts of fruit dry matter were obtained with sulphur application.

N: S ratios obtained were different according to the part of the plant tested. Sulphur fertilization decreased the N: S ratios in shoot, fruit and root. The data obtained indicate that and adequate N: S ratio can insure maximum production of yield.     

Response of wheat to sulfur fertilization

Abstract

Coker 747³ wheat (Triticum aestivum L.) was grown on Keo silt loam (coarse‐silty, mixed, thermic Dystric Fluventic Entrochrepts) with four S sources applied at various rates for two years. The innate S level of this soil was not adequate for optimum grain yield; therefore, additional S significantly increased grain yield and S concentration and decreased N/S ratios in wheat tissue. Minimum S concentration and N/S ratios in plant tissue for maximum yield ranged from 1.3 to 2.73 g S/kg and 9.5 to 19.2, respectively.     

Plant development,agronomic performance and nutritive value of forage maize depending on hybrid and marginal site conditions at high latitudes

Abstract

The objectives of this investigation were to study the effects of marginal site conditions and hybrid on plant development, agronomic performance and nutritive characteristics of forage maize (Zea mays L.) at high latitudes. Field experiments were conducted in 2008 and 2009 at three experimental sites, Kristianstad, Skara and Västerås, at increasing latitudes from 55°–60° N. Experimental design used two replicated randomized complete blocks at each site with three maize hybrids, Avenir (FAO 180), Isberi (FAO 190) and Burli (FAO 210), which were continuously assessed for plant development and harvested at various levels of maturity. The chemical composition and nutritional characteristics of harvested plant materials were analysed and hybrid responses to advancing maturity in terms of yield and nutritional qualities were evaluated. Results showed that maize hybrids required different numbers of accumulated thermal units at sites on varying latitudes to achieve developmental stages. Lowest thermal unit requirements among hybrids were observed for hybrid Avenir, and for sites it was highest for plants grown in the most northern site, Västerås. The most southern site, Kristianstad, was the only site at which all hybrids reached the dent stage (c. 450 g kg^?1 kernel DM), a recommended maturity for ensiling. The DM yields of early maturing hybrid Avenir were consistently lower than those for Isberi and Burli at all the sites. Results also revealed nutritional differences among maize hybrids at a given maturity (DM, g kg^?1), indicating that the effects of maturation should be factored into design of hybrid performance trials. This study highlights the effects of marginal site conditions and hybrids on plant development, agronomic performance and nutritional characteristics of maize hybrids at high latitudes. Further studies on marginal sites are recommended to enlighten the understanding of interaction between environmental and genetic factors on the performance of forage maize.     

Soil nitrogen and carbon status following clover production in louisiana

Abstract

Field studies were conducted for four to seven years on two soils, Tangi silt loam (Typic Fragiudalf, fine‐silty, mixed, thermic) and Dexter loam (Ultic Hapludalf, fine‐silty, mixed, thermic), to determine the effects of phosphorus (P) applications on growth and nitrogen (N) content of white clover (Trifolium repens L.) and subterranean clover (Trifolium subterranum L.) and on ammonium (NH₄ ⁺)‐ and nitrate (NO₃ ^‐)‐N, total N, and organic carbon (C) levels in the soils at the end of the study. Phosphorus applications consistently and significantly increased forage yields and led to significantly higher N yields by the clovers. Increases in plant yields and N₂‐fixation, however, were not reflected in higher soil N and C levels. On Tangi soil, NH₄ ⁺‐ and NO₃ ^‐‐N levels were lowest where no P was applied but no statistically significant differences (P < 0.05) were found among P rates above 20 kg/ha. On the Dexter soils, no significant differences were found at any P application level. Significant differences due to higher clover yields at increasing P rates were not found in total N or organic C . levels in either soil. Greenhouse evaluations showed no differences in bermuda‐grass yield, N concentration, or total N recovery despite increasing subclover yields in the field during the previous seven years. Harvesting nearly all above ground clover growth caused plant roots to be the major N and C contributor to the soil. It is possible that root production was not increased in proportion to forage production as P applications increased. Perhaps increased microbial activities and some leaching losses also minimized accumulations of N and C released by clover roots.     

Response of bermudagrass selections from the Appalachian region to N and P fertilization

Abstract

A greenhouse experiment was conducted to evaluate the influence of N and P fertilization on the yield and forage quality of six cold tolerant bermudagrass (Cynodon dactylon L.) selections from the Appalachian region. Midland bermudagrass and limpograss (Hermarthria altissima) were included for comparison purposes. Each grass was treated with a factorial combination of three N rates (112, 224, and 448 kg N.ha^‐1) and four P rates (0, 25, 75, and 225 kg P.ha^‐1) Two bermudagrass selections from the Appalachian region demonstrated greater dry matter production than Midland bermudagrass. Yields of Quicksand common exceeded those of Midland by 60% to 236% over the range of treatments. High yielding selections were not inferior to low yielding selections when mineral concentrations, neutral detergent fiber, acid detergent fiber and acid detergent lignin levels were considered. The results of this investigation suggest that Quicksand common and Selection 13 merit further study to determine their potential for summer forage production in the Appalachian region.     

Phosphorus source effects on alfalfa yield,total nitrogen content,and soil test phosphorus

Abstract

Recent studies showing a lack of response by alfalfa (Medicago sativa L.) to phosphorus (P) fertilization have raised concerns about the efficacy of commonly used P fertilizer materials in the southwestern United States. Studies were conducted between 1982 and 1985 in southeastern New Mexico to evaluate (i) alfalfa yield response to different P sources, (ii) the effect of P fertilizer source on forage total nitrogen (N) content and leafiness, and (iii) the effect of P fertilizer source on soil test P. Nine P sources were applied annually from 1982 through 1984 at a rate of 58 kg P/ha. Alfalfa was grown during 1985 without fertilization to examine the residual effect of P sources. Triple superphosphate (TSP) and monoammonium phosphate (MAP) gave the highest alfalfa forage yields over the 3‐year application period, but no residual fertilizer effects were observed when fertilization was discontinued. Fertilization did not affect forage leafiness. Except for a small N response in forage total N content in 1984, neither P nor concomitant applied N had a significant effect on forage N content over the 3‐year period. Phosphorus fertilization significantly increased average soil test P for the 3‐year period, but there were no significant differences between treatments. Currently used P materials (TSP and MAP) still appear to be the most efficacious for alfalfa production.     

Effect of Nitrogen Fertilizer Rate and Harvest Season on Forage Yield,Quality, and Macronutrient Concentrations in Midland Bermuda Grass

Bermuda grass [Cynodon dactylon (L.) Pers.] is a major forage for grazing and hay production in the southern United States. The objectives of this study were to determine effects of nitrogen (N) fertilization rate (0, 112, 224, 336, and 448 kg ha^?1), split spring and summer applications of N at the 224 and 448 kg ha^?1 rates, and harvest periods (spring and summer) on forage yield, crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrients (TDN), and concentrations of phosphorus (P), potassium (K), magnesium (Mg), and calcium (Ca in Midland Bermuda grass. Data were collected from 2002 to 2008 as part of an ongoing, long-term soil fertility experiment in southern Oklahoma. Repeated measures analysis of these long-term data showed that forage yield responses to N rate varied with year and harvest time with up to 2.5-fold yield differences among years. Nitrogen fertilization increased CP, TDN, and macronutrient P and Mg and decreased ADF and NDF. Crude protein was increased by ≥50%, and ADF and NDF dropped by up to 25% with the greatest N rate. In general, split N applications did not affect forage yield but produced low-quality forage compared to single N application in spring. Split application of 448 kg N ha^?1 gave forage with CP, TDN, ADF, and NDF similar to the Bermuda grass receiving 336 or 448 kg N ha^?1 as a single application. Spring forage had better forage quality than summer harvests. While N fertilization increased forage Mg and P concentrations by more than 50% during both spring and summer, it had no effect or slight increased K and Ca concentrations. In the southern Great Plains, despite the weather-dependent variability in forage yield of Bermuda grass, N application increase forage quality.     

Approach of yield response curves to steady state

Abstract

Field studies on response of forage grasses to management factors (such as applied N) are generally conducted over multiple years to insure reliability of treatment responses measured. The increased number of observations enhances statistical analysis and separation of means. The question of system behavior over time naturally occurs. Data from a three year study at Watkinsville, GA with coastal and common bermuda ‐grass [Cynodon dactylon (L) Pers.] were analyzed with the logistic model to estimate approach to steady state. Model parameters (A, b, c) showed an exponential shift with time, approaching 90 % of steady state in the third year. The model provided high correlation ( R > 0.98 ) between dry matter yield and applied N.