Mineralizable-N in the soil under various leys and its effect on the yields of following wheat

1968 ◽  
Vol 70 (3) ◽  
pp. 323-329 ◽  
Author(s):  
J. K. R. Gasser

SUMMARYSoil samples taken in the autumn after ploughing ryegrass, clover, and ryegrass/clover leys were used to measure the mineral-N (ammonium-N + nitrate-N) in the fresh soil (mineral-Nfresh), the increase in mineral-N on incubating the fresh soils (Δmineral-Nfresh), and the increase in mineral-N on incubating the re-wetted air-dry soils (Δmineral -Nair-dry). Mineral-Nfresh and Δ mineral-Nair-dry were measured on further soil samples taken the following spring. Values of Δmineral-Nair-dry, not only correlated best with grain yields and N uptakes by wheat without fertilizer-N, but also with yield responses and fertilizer-N recovered from fertilizer-N applied to the winter wheat.Treatment of the ley altered measurements on samples taken in the autumn but not those taken the following spring.Soil samples taken in the autumn 1960 from under three-year grass leys were used to measure mineral-Nfresh, Δ mineral-Nfresh and Δ mineral-Nair-dry Spring wheat was grown in 1961 followed by spring barley in 1962. Further soil samples were taken in spring 1962 after cultivations were complete and before the barley was sown or fertilizers applied.A mineral-Nair-dry was the best measurement to use on soils from under grass leys. Values depended on grass species, and were increased by N applied to the ley. Differences had largely disappeared 18 months later. A mineral-Nalr.dry was positively correlated with grain yields of spring wheat grown both with and without fertilizer-N, and with the yield response or the nitrogen recovered from, a dressing of 56 lb N/acre.With fertilizer-N yields of winter wheat after the mixed leys tended to the same maximum value independently ofmineralizable-N in the soil. After grass leys maximum yields of spring wheat given fertilizer-N increased with increasing mineralizable-N in the soil.

Weed Science ◽  
1995 ◽  
Vol 43 (1) ◽  
pp. 128-133 ◽  
Author(s):  
Gail A. Wicks ◽  
Garold W. Mahnken ◽  
Gordon E. Hanson

Spring small grains were not as competitive with barnyardgrass and witchgrass as winter wheat. Winter wheat grain yields were greater than spring barley or spring wheat in 1986, 1987, and 1988 and oat in 1986 and 1988. Barnyardgrass, stinkgrass, and witchgrass control with glyphosate plus 2,4-D plus atrazine at 0.6 plus 0.8 plus 1.7 kg ha−1was usually less when the herbicides were applied to stubble of spring small grain versus winter wheat due to the advanced weed growth at treatment Barnyardgrass and witchgrass were more difficult to control than stinkgrass, redroot pigweed, tumble pigweed, kochia, and tumble thistle. No-till corn planted into winter wheat stubble had fewer barnyardgrass and witchgrass than corn planted into spring wheat stubble. The addition of metolachlor plus atrazine at 1.7 plus 0.6 kg ha−1eliminated differences among small grain cultivars in weed control in corn. Corn grain yields from winter wheat plots were greater than other small grains in 1989 because of better weed control and more crop residue.


1980 ◽  
Vol 95 (3) ◽  
pp. 583-595 ◽  
Author(s):  
A. Penny ◽  
F. V. Widdowson

SUMMARYAn experiment at Rothamsted during 1958–67 measured effects on yield, on K uptake and on soil K of applying all combinations of 38, 75 and 113 kg N and 0, 31 and 62 kg K/ha per cut to grass leys, which were cut and removed. Soil K was depleted most where most N and least K were given. Annual applications of 0, 33 and 66 kg P/ha were also tested; soil P was not depleted. The grass was then ploughed.In 1968, residual effects were measured by spring wheat. In 1969 and in 1970 104 kg/ha of fresh K was applied on half of each plot; potatoes (1969) and spring wheat (1970) valued residual and fresh effects of K.In 1971 potatoes tested 0, 104 and 208 kg/ha of fresh K, cumulatively with the three amounts given to the grass and also extra K (104 kg/ha) on half-plots, cumulatively with that given in 1969 and 1970. In 1972 winter wheat, and in 1974 and 1975 spring barley, measured residues of all treatments previously applied (the site was fallowed in 1973).Finally, in 1976, potatoes tested 0, 156 and 312 kg/ha of fresh K on whole plots, cumulatively with the previous dressings of K, and also 156 kg/ha of extra K on half-plots, again cumulatively. All these test crops were given basal N.Yields and K contents of wheat at ear emergence and yields of wheat grain were largest after grass given 38 kg N and 62 kg K/ha per cut, because here soil K depletion was least. Wheat grain yields benefited consistently from fresh K. K content of the wheat at ear emergence was a good indicator of the need for K, but K content of grain was not, because it was unaltered by K fertilizer. Barley was a poor test crop for K, because yields of grain were little affected by previous treatments.Percentage K in potato leaves (in July in 1969 and 1971, in August in 1976) and yield of tubers were well correlated. Largest yields in 1969, 1971 and 1976 came where the leaves contained 3·43, 3·76 and 2·82% K, respectively, i.e. from soil containing most exchangeable K, plus most fresh K. There was no indication that maximum yields had been obtained, so the largest amounts (kg/ha) of fresh K tested (104 in 1969, 312 in 1971 and 468 in 1976) were insufficient to counteract depletion of soil K by the grass. Because the grass did not deplete soil P, the test crops benefited only little from either residual or fresh P.


2019 ◽  
pp. 25-30
Author(s):  
Valentina Aleksandrovna Fedorova ◽  
Nina Alekseevna Naumova ◽  
Ekaterina Vasylyevna Yachmeneva ◽  
Yulia Pavlovna Tarasenkova

Objects of research were: spring wheat Saratovskaya 70-st, Cardinal, 3 Curenta, Madam, Nil avocet yr7's, Angarida; spring barley Ratnik-st, Medium 135, grace, Vakula, Brassa; spring oats Showjumping-st, Leo, Bulan, Kuranin. As a result of the study of these varieties of spring crops, the most adapted to local soil and climatic conditions samples were identified. The selected samples were distinguished by high biological plasticity, growth and development rates, maximum use of moisture, as well as the ability to form high grain yields.


Plant Disease ◽  
2003 ◽  
Vol 87 (1) ◽  
pp. 51-55 ◽  
Author(s):  
T. C. Paulitz ◽  
J. D. Smith ◽  
K. K. Kidwell

Rhizoctonia oryzae (teleomorph = Waitea circinata) causes sheath spot of rice and root rot of wheat and barley. R. oryzae commonly is isolated from barley, wheat, and pea plants in eastern Washington and Idaho. Eight representative isolates were tested for virulence on spring barley (Hordeum vulgare cv. Baronesse), soft white winter wheat (Triticum aestivum cv. Madsen), and hard red spring wheat (cv. Scarlet) planted in natural soil in the greenhouse and maintained at 16°C. All isolates caused significant reduction of emergence in barley, but only seven of the eight isolates and one of the eight isolates reduced emergence of winter wheat and spring wheat, respectively. All isolates caused significant stunting and reduction in the number of seminal roots, root length, and number of root tips on wheat and barley. Some isolates also reduced the frequency of fine secondary roots, resulting in a reduction of the average root diameter. Spring barley was more susceptible to R. oryzae than winter or spring wheat. The main effects of both cultivar and isolate were significant, and there was a significant isolate-cultivar interaction. R. oryzae isolate 80042 was the most virulent on barley, whereas R. oryzae isolate 801387 was the most virulent on wheat. The two isolates from pea were intermediate in virulence on wheat and barley. When screening germ plasm for potential resistance, isolates exhibiting the maximum virulence for each host should be used.


1980 ◽  
Vol 3 ◽  
pp. 25-31
Author(s):  
J. F. D. Greenhalgh

The most widely-quoted estimates of straw supplies and usage in England and Wales are those of a working party of the National Farmers Union (1973). They assumed the yield of straw to be 2.8 t/ha, and hence 9.3 Mt from 3.4 M ha of cereals in 1972. (The same yield from 3.7 M ha of cereals in the UK would give 10.4 Mt.) Of the 9.3 Mt, 37% was estimated to be burned in the field or ploughed in, 36% used for bedding, 15% used for feed, and 12% used for other purposes. The figure of 2.4 t/ha (1 t/acre) may well be too low. Short (1974) found straw yields at four Experimental Husbandry Farms over several years to be as follows (t/ha): winter wheat 3.71, spring wheat 4.68, spring barley 2.71, and spring oats 4.54. Wood (1974) surveyed wheat crops in Oxfordshire in 1973 and found yields of 3.7 t/ha. The total quantity of straw available is therefore likely to be considerably in excess of 9.3 Mt and could if necessary be increased further by cutting at a lower level. The accuracy of the National Farmers Union estimate of 0.15 × 10.4 = 1.6 Mt used for animal feeding is also questionable, but this amount would — if it contained 6.5 MJ metabolizable energy (ME)/kg dry matter (DM) — be sufficient to provide only about 7% of the maintenance requirements of all cattle in Britain. On a larger scale, Balch (1977) has calculated that if all the straw grown in Europe were improved by chemical treatment it could provide 80 to 90% of the maintenance requirements of Europe's ruminant livestock. World estimates for the production of straw and other fibrous wastes are given by Owen (1976).


1979 ◽  
Vol 93 (1) ◽  
pp. 87-93 ◽  
Author(s):  
J. Alessi ◽  
J. F. Power ◽  
L. D. Sibbitt

SUMMARYBecause of environmental and economic constraints, we need to determine the effects of nitrogen fertilizer application on nutrient availability and fertilizer recovery, especially in regions of limited rainfall. This study was conducted to provide information on effects of N rate on yields and N recovery by standard and semi-dwarf spring wheats (Triticum aestivum L.) sown at two dates.Ammonium nitrate was applied to spring wheat at rates up to 272 kg N/ha each year for 4 consecutive years. Only grain was removed from the plot at harvest. Wheat types did not differ in grain yields, but these yields were significantly reduced in 2 of 4 years by late sowing. Average grain yields for late sowing were greatest at 34 kg N/ha, but yields for early sowing approached maximum at the 68 kg N for semi-dwarf wheat and 136 kg N/ha for the standard wheat.Semi-dwarf wheat was lower than standard wheat in grain and flour protein concentration and baking absorption. Late sowing (May 30) reduced test weights, flour yield and baking absorption, but increased wheat protein concentration as compared with early sowing (April 30). Leaching of fertilizer N below the 90 cm depth ranged from 152 to 378 kg/ha at the 272 kg N/ha/year rate, and was greater for the late than for the early sowing. Fertilizer N that could be accounted for averaged 87 and 82% for early and late seeding respectively. Water-use efficiency was reduced by late sowing.Soil-water extraction by wheat to the 120 cm depth was greater for high N rates.These 4-year results showed that semi-dwarf and standard wheats had only slight differences in total grain production. Also, for efficient use of applied fertilizer and available soil water, wheat should be sown in the spring as soon as soil and weather conditions permit.


1995 ◽  
Vol 125 (1) ◽  
pp. 25-37 ◽  
Author(s):  
J. Webb ◽  
R. Sylvester-Bradley ◽  
J. D. Wafford

SUMMARYAt 14 sites in the UK, spring wheat (Triticum aestivum) cv. Tonic, was sown on three or four dates at each site between October and March in the 1988/89, 1989/90 and 1990/91 seasons. Responses to spring-applied fertilizer N over the range 0–320 kg/ha were determined. Earlier sowing did not increase uptake of soil N by the crop. Fertilizer N increased grain N offtake by between 25 and 140 kg/ha and yield by between 0·3 and 5·5 t/ha, although grain yield was less responsive to fertilizer N at later sowing dates. Apparent recovery of fertilizer N (AFR) also decreased as sowing was delayed but there was no effect of delayed sowing on the amount of grain produced from each kg of fertilizer N recovered. Because fertilizer N recovery decreased with later sowing, the amount of fertilizer N needed to produce the optimum economic grain yield was not reduced. Neither AFR nor optimum fertilizer (Nopt) was related to optimum yield. Regression of Nopt on the difference between optimum yield and yield without fertilizer N (△y) explained 77% of the variance in Nopt. There was an inverse relationship between △y and soil mineral N (SMN) in spring; regression of △y, on SMN in spring accounted for 29% of the variance in △y Current advisory systems which adjust economic fertilizer N recommendations according to anticipated yield are not justified by these results. Moreover the adjustments made, based on yield expectation, appear about three times as large as those needed to minimize residues of fertilizer N left unrecovered by the crop and to reduce the risk of nitrate leaching in the following winter.


1991 ◽  
Vol 117 (2) ◽  
pp. 241-249 ◽  
Author(s):  
T. M. Addiscott ◽  
R. J. Darby

SUMMARYOptimum applications of N fertilizer, Nopt have been related successfully to the amount of mineral N in the soil, Nmin in some parts of Europe but not always in the UK. If there is a body of mineral N, QN, that ultimately lessens the need for N fertilizer, it will not remain constant in its amount or its position. Mineralization will add to QN, while the nitrate component of QN will be leached downwards.Also, part of QN will be taken up into the crop where it will continue to lessen the need for fertilizer N but will be safe from leaching. A computer model was used to simulate these processes for 23 experiments, covering five sites and five years, in which N opt had been estimated. From these simulations we derived trial values of QN that took account of mineral N to a series of depths on a series of dates. For each date we used the trial values to find the depth for which Nopt was best correlated with QN andassumed that this was the depth, dL, of the lower boundary of QN on that date. Thus dL was a collective value for all 23 experiments. The value of dLincreased throughout the winter and the spring and was very closely related to the cumulative average drainage through 0·5 m soil at Rothamsted. By 15 April, dL, was 1·66 m, a depth that was compatible with observations by others that winter wheat can remove mineral N to a depth of at least 1·5 m. We inferred two likely reasons why Nmin may fail as a predictor of Nopt in the UK: insufficient depth of sampling, and too wide a spread of sampling dates. The values of Nopt were shown to be related satisfactorily to the values of QN computed, without any measurements of mineral N, for appropriate depths on single dates.


1973 ◽  
Vol 81 (1) ◽  
pp. 47-53
Author(s):  
J. B. A. Rodger ◽  
W. D. Gill ◽  
G. K. Shukla

SummaryFourteen trials on spring barley and eleven on winter wheat, grown in the east of Scotland, compared the effects on yield of liquified anhydrous ammonia and solid ammonium nitrate at various levels of application.For grain yield, the optimum N level in these trials was about 100–113 kg N/ha. The object of including in the trials N input levels higher than optimum was attained. Yield response to the two forms of N was similar for both wheat and barley at the different N input levels.Winter injection of anhydrous ammonia was less efficient than spring application. Injection of anhydrous ammonia into young wheat resulted in frequent reduction of plant population and, on occasion, loss of yield.At equivalent rates, anhydrous ammonia caused less lodging than ammonium nitrate; it also appeared to be less readily leached from the soil. Ammonium nitrate gave more rapid early growth and this led to a greater proneness to leaf disease.Considering the complexity of storage and injection equipment required to handle anhydrous ammonia, it is questionable if these agronomic advantages justify its use on cereals where rates of use do not also confer the benefits of cheaper unit cost of nitrogen.


Author(s):  
Uta McKelvy ◽  
Monica Brelsford ◽  
Jamie Sherman ◽  
Mary Burrows

Wheat streak mosaic virus (WSMV) causes sporadic epidemics in Montana which can threaten profitability of the state’s small grains production. One challenge for WSMV management in Montana is that most commercially available wheat and barley cultivars are susceptible to WSMV or their performance under WSMV pressure is unknown. In a three-year field study from 2017 to 2019 winter wheat, spring wheat, and barley cultivars were evaluated for their susceptibility to WSMV and yield performance under WSMV pressure. Plants were mechanically inoculated and WSMV incidence was assessed using DAS-ELISA. There was effective resistance to WSMV in breeding line CO12D922, which had consistently low WSMV incidence, highlighting promising efforts in the development of WSMV-resistant winter wheat cultivars. Moderate WSMV incidence and minor yield losses were observed from WSMV infection of commercial winter wheat ‘Brawl CL Plus’ and MSU breeding line MTV1681. Spring wheat cultivars in this study had high WSMV incidence of up to 100 % in ‘Duclair,’ ‘Egan,’ and ‘McNeal.’ High WSMV incidence was associated with severe yield losses as high as 85 % for Duclair and ‘WB9879CL’ in 2019, demonstrating a high degree of susceptibility to WSMV inoculation. Barley cultivars had considerably lower WSMV incidence compared to spring and winter wheat. Grain yield response to WSMV inoculation was variable between barley cultivars. The study provided an experimental basis for cultivar recommendations for high WSMV pressure environments and identified breeding lines and cultivars with potential resistance traits of interest to breeding programs that aim to develop WSMV-resistant cultivars.


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