High Rates Of Nitrogen Fertilizer Research Articles

Effects of water quality and frequency of irrigation on growth and yield of barley ( Hordeum vulgare L.)

A field trial on a loamy sand soil was carried out to study the effect of three irrigation waters with different qualities on growth and yield of ‘Gesto’, a barley ( Hordeum vulgare L.) cultivar. Three irrigation water quality treatments (canal irrigation water, drainage water, and mixed canal and drainage waters at 1:1 ratio) were imposed with two irrigation frequencies (I and 2 week intervals). In addition, nitrogen and phosphorus fertilizers were applied at different rates. Barley grain and straw yields were significantly decreased under the use of drainage water (EC 10.7–16.7 dS m −1), attributed mainly to reduction in the number of spikes per plant and grain weight. The mixed irrigation water (EC 6.8–9.9 dS m −1) produced high seedling emergence and good vegetative growth, which was followed by high grain and straw yields. These yields were not significantly different from those under fresh canal irrigation water (EC 2.8–3.9 dS m −1). Thus, mixed water could be another alternative for irrigation under similar experimental conditions especially with high rates of nitrogen (250–350 kg ha −1) and phosphorus (90 kg ha −1) fertilization at weekly irrigation intervals, which could eventually save more fresh irrigation canal water for other cultivated crops.

Effect of shading and nitrogen application on yield, grain size distribution and concentrations of nitrogen and water soluble carbohydrates in malting spring barley ( Hordeum vulgare L.)

Experiments to investigate the effects of periods of low radiation, combined with different rates of nitrogen fertilization, on growth, grain yield, mean grain weight, grain size distribution and concentrations of nitrogen and water soluble carbohydrates (WSC) were carried out in 1991 and 1993. The low radiation (60% of ambient radiation) was achieved by placing shading nets in fields of barley (cv. Prisma). There was an unshaded control (S1), plus three shading period treatments during the main phenological phases, with three rates of nitrogen fertilization (unfertilized control, 90 kg ha −1 minus soil nitrogen and this rate plus 60 kg ha −1 at the flag leaf stage). It was found that total grain yield was 5% lower after shading during tillering (S2), 35% lower after shading during stem elongation (S3) and 45% lower after shading during grain filling (S4). Treatments S2 and S3 considerably reduced the concentration of WSC in plant organs and increased the nitrogen concentration and, in general, the concentrations returned to the values of the control after the shading period. The S3 treatment markedly reduced the number of grains m −2, mainly because there were 35% fewer grains per spike. This treatment resulted in a mean grain weight 14% above that of the control, but only in 1991. Weather was probably responsible for this disparity: in 1991, the spring was cold and wet and the summer was warm and dry, but in 1993 the spring was warm and dry and the summer was cool and wet. The S4 treatment reduced mean grain weight by 40% in 1991 and by 25% in 1993 and shifted the median of the size distribution towards smaller grains in both years. In S4, the N concentration in the grains was markedly increased, resulting in unacceptably high protein concentrations (14–21%) for malting quality. Higher rates of nitrogen fertilization increased leaf area index (LAI), total dry matter production and grain N concentration. Nitrogen had a positive effect in establishing yield potential because it increased grain number per unit area; however, it did not improve assimilate supply during grain filling, and hence grain number and mean grain weight were negatively correlated. Only in 1993 did nitrogen increase grain yield. It is concluded that shading during the growing period and high rates of nitrogen fertilization adversely affect the quality (in terms of grain size, size distribution and grain nitrogen concentration) of malting barley.

Effect of fertilizers on soil pH and performance of apple and pear trees. II. Grown in different soils in the orchard

Abstract In the apple orchard, trees fertilized with calcium nitrate resulted in the highest soil pH (6.4) whereas the lowest pH (4.7 and 4.6) occurred with ammonium nitrate and with mono‐ammonium phosphate (MAP) applications, respectively. Soil pH values were lowest with the high rates of nitrogen (N) fertilizers. Red skin color of ‘Delicious’ apples was generally improved with calcium nitrate fertilization, higher soil pH values, and with lower fruit manganese (Mn) concentrations or with lower N fertilizer rates. Incidence of bitter pit was lowest for trees fertilized with ammonium nitrate or calcium nitrate. In the pear orchard, the lowest soil pH (4.2) occurred when trees were fertilized with the high rate of MAP and the highest soil pH (4.8) occurred with the high rate of calcium nitrate applications. Fruit size was slightly smaller on trees fertilized with the high rate of MAP. Lowest incidence of superficial cork or green stain fruit disorders occurred on trees receiving the high rate of calcium ni...

Effects of agronomic practices on free fatty acid levels in the oil of Ontario-grown spring canola

Spring canola (Brassica napus) seed grown in Ontario frequently exhibits elevated levels of free fatty acids (FFA) in the oil. The objective of this study was to determine the effects of various agronomic practices on FFA levels. Several field experiments were conducted in 1989 and 1990, and one experiment was conducted in 1987. FFA levels in the oil were higher in 1989 than in 1990. Two cultivars, Kristina and Global, were included in most experiments. The cultivar Kristina exhibited consistently lower FFA levels than the cultivar Global, averaging 42% less over years and treatments. Global averaged 1.31 and 0.62% FFA in 1989 and 1990, respectively. Decreasing seeding rates raised FFA levels in both cultivars in 1989 and in Global in 1990. Increasing rates of nitrogen (N) fertilizer increased FFA in Global in 1989. The removal of drought stress by irrigation during seed filling decreased FFA in Global by 46% in 1989. A combination of high N, low seeding rates, and no irrigation increased FFA in both cultivars in 1990. Delays in planting date resulted in higher FFA in 1987. The effect of these agronomic practices on yield and seed oil concentration were also reported. Applications of potassium or boron fertilizers did not affect FFA, nor did weekly applications of the fungicide, benomyl, or dosing plants with elevated levels of atmospheric ozone. The problem of elevated FFA can be diminished by avoiding excessively high nitrogen fertilizer rates and low seeding rates and by selection of low-FFA cultivars. Key words: Canola, free fatty acids, irrigation, ozone, planting date, oil content

Arginine in concord grape as affected by high soil nitrogen fertilization and daminozide

Abstract Own rooted Concord grapevines, Vitis labruscana B, planted in 1981, trained to the Geneva Double Curtain training system, were used to investigate their response of levels of total arginine of different vine organ to high rates of soil nitrogen fertilization and the growth regulator daminozide. Arginine in fruit juice, not in the leaf petiole or maturecanes, is recommended as an indicator of nitrogen status based on the results of this study. Daminozide did not appear to be involved in the nitrogen nutrition of Concord grapes. Soil nitrogen fertilization increased the total nitrogen content of the leaf petioles both in 1986 and 1987. The arginine content of the fruit juice was not increased in 1986 as a result of nitrogen fertilization, but was increased at three of the four harvest dates in 1987. Daminozide did not affect the arginine content of the fruit juice except at the third harvest date in 1987. Higher nitrogen rates did not increase the arginine content of the leaf petiole or mature cane...

The effect of irrigation and nitrogen on the yield and composition of peppermint oil (Mentha piperita L.)

Peppermint was harvested twice during the growing season. Harvest 1 was conducted on 16 February 1979, and the subsequent regrowth was harvested on 25 April 1979. High peppermint oil yields were associated with high rates of nitrogen fertilizer (100, 200 and 300 kg nitrogen/ha), and high levels of irrigation (50 mm per week) throughout the last half of the growing season. The composition of oil extracted from herb at the commercial harvest date was not significantly affected by either nitrogen or irrigation treatments. The oil yield from regrowth within the same growing season was significantly affected by irrigation and nitrogen treatments applied prior to the first harvest. When 300 kg nitrogen/ha and 50 mm of irrigation weekly (during the last half of the growing season) were applied, the oil yields from regrowth approached the commercial yield obtained from one harvest. Oil from regrowth contained high levels of menthol, menthyl acetate, menthofuran and limonene, and low levels of menthone and cineole. The possibility of obtaining two commercial harvests of peppermint per season, under southern Tasmanian conditions, is discussed

Role of continuous nitrogen fertilization on nutrient composition of leaves sampled at various stages of growth and on yield of yam (Dioscorea rotundata)

Abstract White yam (Dioscorea rotundata cv. Olonko) was grown consecutively for three growing seasons, i.e. from February to October of 1975, 1976 and 1977, and treated with six levels of nitrogen, viz: 0, 40, 60, 120, 160 and 200 kg N/ha in the field. Leaf samples were taken at four stages of growth as follows: vegetative, tuber formation, tuber development and tuber maturation, and analyzed for NO3‐N, P, K, Ca and Mg. Increasing nitrogen fertilization consistently increased leaf‐NO3‐N, particularly at the vegetative stages of growth, while no consistent trend was established for leaf‐P. Leaf‐K was increased at low rate of nitrogen fertilization during tuber formation and maturation whereas leaf‐Ca increased only at tuber maturation in the presence of higher rates of nitrogen fertilization. There was a marked increase in leaf‐Mg at all stages of growth when N treatment was increased to 200 kg N/ha. A positive correlation (r = 0.84∗∗∗) was obtained for leaf‐K at the vegetative growth stage with tuber yield, while leaf‐Mg was positively correlated with tuber yield at vegetative (r = 0.46∗), tuber formation (r = 0.50∗) and tuber development (r = 0.67∗∗) stages. All other elements were negatively correlated with yield at all stages of growth. Tuber yield was highest at the 200 kg N/ha treatment.

Role of continuous nitrogen fertilization on nutrient composition of leaves sampled at various stages of growth and on yield of yam (dioscorsa rotunoata)

Abstract White yam (Dioacosa rotundata cv. Olonko) was grown consecutively for three growing seasons, i.e. from February to October of 1975, 1976 and 1977, and treated with six levels of nitrogen, viz: 0, 40, 80, 120, 160 and 200 kg N/ha in the field. Leaf samples were taken at four stages of growth as follows: vegetative, tuber formation, tuber development and tuber maturation, and analyzed for NO3‐N, P, K, Ca and Mg. Increasing nitrogen fertilization consistently increased leaf‐NO3‐N, particularly at the vegetative stages of growth, while no consistent trend was established for leaf‐P. Leaf‐K was increased at low rate of nitrogen fartilization during tubar formation and maturation whereas leaf‐Ca increased only at tuber maturation in the presence of higher rates of nitrogen fertilization. There was a marked increase in leaf‐Mg at all stages of growth when N treatment was increased to 200 kg N/ha. A positive correlation (r = 0.84***) was obtained for leaf‐K at the vegetative growth stage with tuber yield...

Nitrogen and phosphorus requirements of wheat sown by minimum tillage into rice stubble and the effects of rice stubble treatment

Egret wheat was sown into rice stubble using a minimum cultivation technique called seedavation. Nitrogen was surface applied as sulphate of ammonia in 1974 and ammonium nitrate in 1975 at 0,60 and 120 kg N ha-1. Phosphorus as single superphosphate was drilled with the seed at 0 and 17.5 kg P ha-1. The effects of burning, incorporating and removing rice stubble were compared. Large grain yield responses to nitrogen were achieved with yields up to 5 t ha-1 despite the use of minimum tillage. Tiller numbers were highly correlated with yield. No yield response to phosphorus was obtained. Low protein levels (less than 10%) suitable for biscuit wheat were obtained even at the high nitrogen fertilizer rates. The effect of stubble treatment varied between years; in 1974 it had no effect on yield; however, in 1975 removing or incorporating stubble reduced yields compared with burning the stubble. These results indicate that in rice growing areas a significant rise in wheat yields can be achieved through the use of higher nitrogen fertilizer rates.

The relationship of grain shrivelling to the milling and baking quality of three winter wheat cultivars grown with different rates of nitrogen fertilizer

It is generally assumed that poorly filled, or shrivelled wheat grain gives poor flour yields on milling, due to low endosperm content. Quality standards therefore often impose minimum limits of specific weight and grain size with the intention of excluding shrivelled samples. Although milling and baking quality are partly genetically determined, certain of their components are strongly influenced by environment. Flour protein, loaf score and alpha-amylase activity may be improved by nitrogen fertilizer (Pushman & Bingham, 1976), although the reaction of other characters is sometimes less favourable. Reduced flour yields and deterioration of flour colour have been reported at high rates of nitrogen fertilizer (Fuller & Stewart, 1968), and grains frequently become smaller and more shrivelled as application rate is increased (Bayles, 1977 c).

SOME FACTORS AFFECTING PASTURE PRODUCTION IN SOUTHLAND

The pattern of production from permanent pastures on two major soil groups in Southland and some factors affecting production are discussed. Production was shown to be lower on the summer droughtprone YGE/YBE intergrade soils compared with the wetter southern YBE. The major proportion (80%) of the production occurred in spring and summer. Grasses contributed two-thirds and white clover one-third of the annual production. Inadequate mineral nitrogen levels in soils over the spring result in seasonal responses to nitrogen fertilizers. The use of high rates of nitrogen fertilizer at regular intervals throughout the year increased total pasture production by about 25%. The clover cyst nematode was shown to reduce white clover establishment and production in field trials.

Influence of fertilizer, irrigation, and storage treatments on nitrate-N content of potato tubers

A survey was undertaken to investigate the nitrate-nitrogen (NO3-N) content of potatoes grown on different soil types with different fertilizer and irrigation treatments. Tuber nitrate-N contents were determined immediately after harvest and after periods of storage of up to 210 days. Nitrate-N in tubers (dry weight basis) ranged from low values of 82 to 122 ppm for low nitrogen fertility levels to a maximum of 192 to 285 ppm at the highest nitrogen rates, where irrigation was applied at optimum levels. The average nitrate-N in tubers under such conditions was 150 to 160 ppm. Where irrigation management was less than optimum, the nitrate-N content of tubers increased, reaching an average maximum value of 786 ppm at the highest fertilizer rate. The study showed that the nitrate-N level in tubers increased with nitrogen fertilization rates, although there was not a linear relationship between N fertilizer rate and tuber nitrate-N. The highest nitrate-N levels obtained in the tubers under proper irrigation management, even with 800 lb N/A, did not exceed 300 ppm nitrate-N and were usually less than 200 ppm. Data collected from this study suggest that improper irrigation, especially with high nitrogen fertilizer rates, results in a dramatic increase in nitrate-N level in the tubers. Some individual tubers contained over 1200 ppm nitrate-N. There was an apparent slight increase in nitrate-N in the tubers with storage, although this increase was not consistent.

Effects of irrigation, Nitrogen Fertilization, Plant Population and Variety on the Physico-Chemical Properties of Maryland Tobacco: I. Agronomic Effects

AbstractIrrigation experiments on Maryland tobacco have been conducted since 1955 on Monmouth fine sandy loam, a typical tobacco soil of Southern Maryland. An overhead sprinkler system was employed. Moisture levels in the soil were studied, using Bouyoucous gypsum blocks and tensiometers. The following conclusions were made from this study:1. In a year of severe drought, 1966, ample irrigation increased yields, unit value and total value. Irrigated yields were 175 per cent of non-irrigated; unit value was 141 per cent, and total value of irrigated tobacco was 247 per cent of non-irrigated.2. Nitrogen fertilizer rates of 100.9, 134.5 and 168.1 kg ha were used. Under irrigation, gains in yield and total value, and some loss in unit value were obtained from the first added increment of fertilizer nitrogen above the base amount. Addition of the second increment produced smaller gains in yield, a greater loss in unit value, and losses in total value.3. In the absence of irrigation, the supply of soil water could limit nitrogen assimilation by the plants. The higher rates of nitrogen fertilization were effective in increasing yield and total value over the lower increments. Even unit value was not adversely affected.4. The Wilson broadleaf variety of Maryland tobacco consistently outyielded the Catterton medium broadleaf variety, but due to lower unit value, probably caused by darker colours, it had a lower total value.5. Plant populations of about 18000 per hectare produced increased yields and gross return over a population of about 12000. Populations of 24000 plants per hectare were excessive in most cases, and produced losses in yield and unit value.6. Comparative response to irrigation depends on severity of drought, but late depletion of soil moisture levels may prevent the full potential development of the crop, and result in lower yields and total value.

Nitrate‐nitrogen Accumulation under Bromegrass Sod Fertilized Annually at Six Levels of Nitrogen for Fifteen Years1

AbstractAn old bromegrass sod established prior to 1929 and fertilized annually since 1954 with nitrogen at rates from 0 to 298 kg/ha responded with increased forage, protein, and seed yields. Nitrate‐N content of the soil profile after 15 years of fertilization was analyzed using an Orion 401 specific ion meter with a NO3‐N electrode to determine the possible pollution of ground water with nitrates attributable to increased nitrogen fertilization. Nitrate‐N content was similar below 106.7 cm to a selected depth of 137 cm during late April and of 152 cm during late June and August in 1969 under each of six fertility treatments. Highest concentration of NO3‐N was found in the soil profile from 15.2 to 61.0 cm in depth. Results suggest apparent lack of NO3‐N movement and accumulation in fine‐textured soils under northern climatic conditions even under high rates of continuous nitrogen fertilization.

Effect of Paraquat on the Nitrogen Content and Regrowth of Coastal Bermudagrass (Cynodon dactylon (L.) Pers.)

AbstractThe nitrogen content and regrowth potential of 'Coastal' bermudagrass (Cynodon dactylon) was investigated following treatment with paraquat. Two rates of fertilizer, 73.7 kg /ha and 1.5 kg/ha, were applied before paraquat application. Five weeks later paraquat was sprayed at the rate of 0.45 kg/ha.Grass samples were collected at intervals and freezedried, and nitrogen content was determined. Regrowth was evaluated as height and number of new shoots developed from cut stubble of paraquat‐treated plants.High nitrogen fertilizer applications significantly increased the nitrogen content of Coastal bermudagrass. When these plants were sprayed with paraquat, loss of nitrogen occurred less rapidly than in control plants. Seven weeks following paraquat treatment, the number of shoots produced in regrowth was only about half that of controls. However, there was no difference in the total fresh weight. These results suggest the possibility of using high rates of nitrogen fertilization and the subsequent curing of foliage with paraquat to maintain protein content for an extended period.

The effect of low, medium and high nitrogen fertilizer rates on the storage of sugar beer roots at high and low temperatures

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Saline soils under dryland agriculture in southeastern Saskatchewan (Canada) and possibilities for their improvement

Yields of wheat, when grown on saline soil under dryland conditions were increased by treatments such as mulch, manure, high rates of nitrogen and phosphorus fertilizers in combination or alone and by Krilium. On the other hand, all treatments, with the exception of Krilium, had no effect on the salinity concentrations of the 0–6 inch soil layer. It was concluded that all three factors, namely fertility improvement, structure improvement, and moisture perservation contributed towards higher yields on saline soil. The return, however, as evidenced from field and growth room experiments, was decreasing with increasing salinity. This reduction in responsiveness, which is significant for practical agriculture, was ascribed mainly to a reduction in the availability of nutrients to plants when grown on saline soils.

Effects of Nitrogen and Sulfur Fertilization on Yield and Malting Quality of Barley1

SynopsisBarley yields in three field experiments were increased by nitrogen and sulfur fertilization with a significant nitrogen × sulfur yield interaction. The higher rates of nitrogen fertilization decreased kernel size, increasd barley, malt, and wort nitrogen, and reduced malting quality. Sulfur fertilization had no effect on nitrogen content but increased the enzymatic activities of the malts.

THE EFFECT OF NITROGEN AND PHOSPHORUS FERTILIZERS ON THE YIELD AND PROTEIN CONTENT OF SPRING WHEAT GROWN ON STUBBLE FIELDS IN SOUTHERN ALBERTA

Varying rates of nitrogen and phosphorus were applied to hard red spring wheat grown on stubble fields at three locations in southern Alberta in 1955 and 1956. Significant yield increases were obtained at the three locations in 1955 as a result of applications of nitrogen. At two of the three locations further increases in yield resulted from the addition of phosphorus. In 1956 significant yield increases were obtained at two of the three locations following nitrogen applications, and at only one of these locations did the addition of phosphorus result in further significant increases in yield. At two of the three locations in both 1955 and 1956 high rates of nitrogen fertilizer caused significant increases in protein content over the unfertilized check. Phosphorus additions significantly reduced the effect of nitrogen on the protein content at one location in one year, but had no consistent effect in the other experiments. The experimental results indicate that, when moisture is adequate, more than 40 lb. of nitrogen per acre, and at least 80 lb. per acre in some cases, must be applied before increases in protein content of spring wheat can be expected.

A BIOCHEMICAL BASIS FOR COPPER-NITROGEN BALANCE IN TUNG

Work on tung (5, 6) has clearly established that a close relationship exists between the severity of copper deficiency and the amount of nitrogen fertilizer supplied to the plant. Normal plants free from the symptoms of copper deficiency can be produced under conditions of low nitrogen supply when the copper supply is sufficiently high (fig. 1). When high rates of nitrogen fertilizers are supplied to plants on low copper levels, the plants usually show severe symptoms of copper deficiency, such as necrosis of the leaves and eventual dieback of the terminals (fig. 2). Such affected plants can be made to resume normal growth by application of copper sulphate either to the soil or as a spray to the leaves. Physiological studies (5) have shown that copper deficiency is characterized in tung by the formation of abnormal amounts of complex nitrogen compounds at the expense of the carbohydrate reserves of the plant. The result is a net increase in content of the copper-deficient material over that of the normal on the basis of either per plant part or percentage of dry weight. Lucas (10) has also reported an abnormally high percentage in copper-deficient plants in comparison with those of high copper content. In the previous work with tung (5) was determined as hot-waterinsoluble nitrogen content, and in the work of Lucas (10) as amino-N content. It is thus impossible to determine whether the high protein values obtained represent actual quantitative differences or a qualitative difference in composition such as would result from a high ratio of basic polyamino to monoamino acids. Studies were therefore made of the amino acid