Yields of crop dry matter and nitrogen in long-term barley rotation trials at two sites in northern Syria

1995 ◽  
Vol 124 (3) ◽  
pp. 389-402 ◽  
Author(s):  
M. J. Jones ◽  
M. Singh

SUMMARYTrials were established at two sites in 1982 to compare six 2-course rotations, in which barley alternated with feed legumes (pure or mixed with barley), fallow or barley, in partial factorial combination with different N and P fertilizer regimes. This paper summarizes data from the second to the seventh cropping seasons.Barley yielded most after fallow and more after legumes than after barley; but, on the basis of total dry matter production over both courses, barley-legume rotations outyielded barley-fallow and barley-barley rotations. In terms of net nitrogen offtake, which may be taken as a rough measure of feed value, barley-legumes surpassed the other rotations by c. 100% at both sites, whether the comparison was made on values obtained from plots with or without added fertilizer. Of the legumes, Lathyrus sativus was slightly more productive than Vicia saliva, and this carried over into the rotational yield of both dry matter and nitrogen. Rotations involving pure legumes were slightly more productive than those involving legume/barley mixtures.Yields of all crops and rotations varied greatly from year to year depending on rainfall. Those of the barley-fallow rotation were much less variable than those of the barley-barley rotation at the wetter site (323±103 mm), with the barley-legume rotation intermediate; but variability was much greater at the drier site (250±79 mm), with much less difference between rotations. Nevertheless, fertilizer use and rotations including legumes gave a significant yield advantage under the driest conditions.

2016 ◽  
Vol 51 (9) ◽  
pp. 1633-1642 ◽  
Author(s):  
Claudio Hideo Martins da Costa ◽  
Carlos Alexandre Costa Crusciol ◽  
Jayme Ferrari Neto ◽  
Gustavo Spadotti Amaral Castro

Abstract The objective of this work was to evaluate the long-term effects of the surface application of lime on soil fertility and on the mineral nutrition and grain yield of soybean, and of black oat and sorghum in crop succession. The experiment was carried out on a clayey Oxisol, in a randomized complete block design, with four replicates. Treatments consisted of lime the rates of 0, 1,000, 2,000, and 4,000 kg ha-1, applied in October 2002 and November 2004. Soil samples were collected at five soil layers, down to 0.60-m depth. Surface liming was effective in reducing soil acidity and increasing Ca2+ and Mg2+ contents in the subsurface. Moreover, it increased available phosphorus contents and soil organic matter in the long term (48 to 60 months after the last lime application). Surface liming improved plant nutrition, mainly for N, Ca, and Mg, and increased dry matter production and grain yield of the crops, even in years with regular distribution of rainfall. The greatest productivities of soybean, black oat, and sorghum were obtained with the respective estimated lime doses of 4,000, 2,333, and 3,281 kg ha-1, for shoot dry matter, and of 2,550, 3,555, and over 4,000 kg ha-1, for grain yield.


1987 ◽  
Vol 67 (1) ◽  
pp. 21-34 ◽  
Author(s):  
L. M. DWYER ◽  
D. W. STEWART

Barley (Hordeum vulgare ’Bruce’) was grown in a greenhouse under three photoperiods (8, 12 and 16 h) and nine watering treatments, resulting in different timing, duration and intensity of water stress. Phenological development, according to the Feekes scale, was monitored three times a week and leaf area was measured weekly from tillering to ripening. Final aboveground and root dry matter production and grain yield were obtained at harvest. Phenological observations were fit to a nonlinear photothermal model that expressed phenological development as a function of heat units modified by photoperiod. In the absence of water stress, maximum leaf area was directly proportional to photoperiod and the time of maximum leaf area was delayed at longer photoperiods. Water stress hastened leaf area senescence and, in general, the more severe the stress, the greater the reduction in leaf area. Most stress treatments also resulted in lower shoot/root ratios than found in well-watered controls, as well as significant yield reductions. Reduction in biomass and yield components appeared independent of photoperiod. In contrast, not only was phenological development rate proportional to photoperiod, but the effect of water stress on development rate was modified by photoperiod. Development was significantly delayed by several water stress treatments; no treatment significantly hastened development. A stress period from tillering to the beginning of stem extension caused the largest, and most consistent, delay and the duration of the delay was inversely proportional to the photoperiod.Key words: Barley, degree days, phenology, leaf area, biomass


2004 ◽  
Vol 142 (2) ◽  
pp. 141-151 ◽  
Author(s):  
J. ERIKSEN ◽  
F. P. VINTHER ◽  
K. SØEGAARD

Grass-legume associations may offer a way of improving the N efficiency of dairy farming, but may also have an adverse impact on the environment by increasing leaching losses. Nitrate leaching from four cropping sequences with different grassland frequency and management (long-term grazed, long-term cut, cereals followed by 1 and 2-year grazed leys) were investigated on a loamy sand in central Jutland for both unfertilized grass-clover (perennial ryegrass (Lolium perenne L.)/white clover (Trifolium repens L.)) and fertilized perennial ryegrass (300 kg N/ha) swards during 1997–2002. Furthermore, 1 year (2001) of N2 fixation in 1-, 2- and 8-year-old grass-clover pastures was determined. Nitrate leaching from grazed unfertilized grass-clover was always considerably lower than from grazed fertilized ryegrass. The effect of grassland age on nitrate leaching was insignificant in grass-clover but clear in grazed ryegrass, where levels increased dramatically with sward age. In production years 6–8, leaching from grass-clover was only 9–13% of the comparable losses from ryegrass. Under the cutting regime grass-clover showed a significant reduction in both yield and N-removal with increasing sward age, whereas for ryegrass these figures did not show any decreasing trend. N2 fixation was lower in 8-year-old swards compared with fully established 2-year-old swards as a consequence of lower dry matter production, lower clover content and a lower proportion of clover-N derived from the atmosphere. The results from the present study indicate that the higher leaching losses observed in fertilized grass compared with unfertilized grass-clover systems were caused by (1) a reduction in N2-fixation in grass-clover over time and (2) a reduction in dry matter production in grass-clover over time, lowering the grazing intensity and the recycling of grassland N via animal excreta.


1967 ◽  
Vol 7 (29) ◽  
pp. 501 ◽  
Author(s):  
DF Cameron

The flowering times of 58 collections of Townsville lucerne from typical sites in northern Australia have been recorded in three spaced plant experiments near Townsville. Thirty-six collections were grown in 1963-64, 15 in 1964-65, and 17 in 1965-66. All the late flowering collections came from sites receiving at least 45 inches annual rainfall. The five collections from south of Rockhampton were all of the early or midseason type and all collections from the far northern areas were late flowering. Partial regression analysis was used to relate the flowering time of a collection to the rainfall (for the five months interval from January to May) and latitude of the collection site. In the first two experiments rainfall, latitude and (latitude)2 all contributed significantly to the regressions, but in the third experiment only rainfall was significant. Correlation coefficients for 1963-64, 1964-65, and 1965-66 were +0.83, +0.97, and +0.93 respectively. A selection was derived from a collection by bulking seed from single spaced plants selected for uniform flowering time and growth habit. The dry matter yields of some collections and selections were compared in two sward experiments near Townsville in 1964-65 and 1965-66. In 1964-65 there were significant yield differences between collections (experiment A, P<0.01) and between selections (experiment B, P<0.001). There were differences in the rates of vegetative growth and differences in the length of growing season, with late flowering types being able to make better growth late in the season when early types were flowering and seeding. Types with erect growth habit had the highest yields and seemed to compete better with sown grasses than the prostrate types. There were no significant yield differences in 1965-66, a very dry year, and the late flowering types failed to set seed.


1979 ◽  
Vol 19 (99) ◽  
pp. 437 ◽  
Author(s):  
AC Andrews ◽  
FC Crofts

Four ecotypes of hybrid Bermudagrass (Cynodon dactylon) were compared with common couch (C. dactylon) and kikuyu (Pennisetum clandestinum) at five sites in coastal districts of New South Wales. The sites were Grafton and Coaldale (Lat. 30�S), Mitchells Island (Lat. 32�S) and Richmond and Badgerys Creek (Lat. 34�S). Hybrid Bermudagrass ecotypes 6389 and 692 were established quickly at all sites while ecotypes 71 9 and 632 were satsifactory. Kikuyu was strong at all sites except Grafton but the rate of establishment of common couch was poor. At the frost-free sandy site of Mitchells Island, Bermudagrass ecotypes 719, 692, 6389, and 632 outyielded kikuyu by 75, 65, 65 and 35%, respectively. However, at Grafton and Coaldale, the highest yielding Bermudagrass ecotype, 719, had only 35% higher production than kikuyu. At the frost prone southern sites of Richmond and Badgerys Creek, the annual production of kikuyu was equal to that of ecotypes 719, 6389, 692 and 632. Common couch yields were equal to kikuyu at all sites except at Richmond. At Mitchells Island, the hybrid Bermudagrasses outyielded kikuyu in spring, summer and early autumn but in the late autumn kikuyu had equal and sometimes higher growth rates than the best Bermudagrasses. In winter, the growth of both species was negligible, although kikuyu, unlike the Bermudagrasses, did produce some new shoots at the base of the sward. Data on persistence under grazing were collected from only three of the sites but trends were similar to establishment. Ecotype 6389 had the highest persistence rating of the Bermudagrasses. Kikuyu failed at the poorly drained sandy site of Grafton but remained strong at the other sites. It was concluded that hybrid Bermudagrasses were of potential value for pastures in New South Wales, especially for sites with sandy soils and low frost incidence.


1969 ◽  
Vol 49 (3) ◽  
pp. 339-349 ◽  
Author(s):  
H. Gasser ◽  
L. Lachance ◽  
P. Gervais

In two experiments, one with alfalfa and the other with birdsfoot trefoil, we have been able to show that a late cut in October does not adversely affect dry matter yield (DAI) of the legumes. Three cuts during a harvesting season ending on September 5 were detrimental to alfalfa, since lower yields were obtained the following year of harvest. Birdsfoot trefoil varieties were affected differentially. Three cuts did not affect the yield of Viking the following year, but did so of Empire. Significant differences in dry matter yields were obtained between DuPuits and Vernal and between Viking and Empire. Protein in the forage followed inversely the same pattern as that of DM yields, that is, where the intervals were shortest, the protein content was highest, and conversely. The total available carbohydrate and the nitrogen content of the roots were lowest following the treatments which had the shortest intervals between them.


1972 ◽  
Vol 23 (6) ◽  
pp. 945 ◽  
Author(s):  
JF Angus ◽  
R Jones ◽  
JH Wilson

Under conditions of adequate moisture an erect-leaf barley cultivar, Lenta, responded to an increase in density (resulting from doubling of the sowing rate) with increases in dry matter production and in grain yield, whereas the cultivar Research, which has long lax leaves, responded with decreases in dry matter production and yield. In a study of canopy structure and its effects on light interception and utilization, it was found that in Research, with a leaf area index (LAI) of 6.1, the leaves were concentrated near the canopy surface and a relatively small proportion of the above-crop light penetrated through this layer. The net crop photosynthesis of this canopy (measured in a field assimilation chamber) was 3.8 g CO2/m2.hr when visible radiation was 313 W/m2. With Lenta (LAI 7.0) on the other hand, leaves were concentrated in the middle layers of the canopy and the light was more evenly distributed throughout the canopy. The net crop photosynthesis with the same radiation as for Research was 4.3 g CO2/m2.hr. The relative rates of photosynthesis at various levels in the canopies were determined by introducing 14CO2 into the assimilation chambers enclosing the cultivars and observing where the 14C was fixed. With Research most of it was localized near the canopy surface while with Lenta most of it was near the centre of the canopy. Of the 14CO2 taken up, 7 % was fixed in the leaf sheaths of Research and 12% in those of Lenta.


2003 ◽  
Vol 1 (1) ◽  
pp. 35
Author(s):  
J.L. Martin Polo ◽  
C.J. Valle Gutierrez ◽  
A. Blanco de Pablos ◽  
M.E. Sánchez Rodríguez

In two «dehesa» grasslands with different soils, one over slate and the other over granite, studies were carried out toinvestigate the influence that phosphoric fertilization, surface tillage of pastures and oat sowing have on the primaryproduction and its nutritive value, on the index of utilization of raining water, and on the evolution of oat stubble withtime. Additionally, economic studies of the previous results have been carried out. Phosphoric fertilization and superficialtilling of pastures did not have a relevant influence on the primary production. Additionally, in the successive regrowthover oat stubble there was no response to phosphoric fertilization. The production increments with respect tocontrols are related to the preparatory tillage for sowing the oats, and the changes that the vegetation experimented.This effect decreased with time. The dry matter production in the oat treatments was higher than in the pastures, bothin slate and granite soils. In dehesa systems the use of raining water for the production of 1 kg dry matter ha-1 was verylow, and, on the average, 0.278 and 0.588 l m-2 were needed in pastures, but this amount decreased significantly in theoats: 0.059 and 0.110 l m-2 in slates and granites, respectively; with better use of the water in the more fertile soils. Theeconomic response to the oat sowing was about 252 and of 160 euros ha-1 year-1 in slates and granites, but there was noeconomic response to the fertilization and superficial tilling of pastures during the period of the experiment.


2019 ◽  
Vol 13 ((03) 2019) ◽  
pp. 372-379
Author(s):  
Rodrigo Miranda Moraes ◽  
Fernanda Carlota Nery ◽  
Mayara Caroline Carvalho Pinto ◽  
Renato Paiva ◽  
Sandro Barbosa

Hibiscus acetosella (Malvaceae) is a shrub of great importance for landscaping, food and medicinal purposes. The objective of this study was to preserve H. acetosella germplasm by seed cryopreservation. Half of the seed batch was scarified and the other half was kept intact. Cryopreservation occurred by immersion in liquid nitrogen for 1 hour. Moisture content (MC%), germination percentage (G%), germination speed index (GSI), normal seedling formation (NS%), shoot length (SL), dry matter (DM), biometry and plant survival were evaluated after treatment. MC% ranged between 7.7% and 6.65% in intact and scarified seeds, respectively. Scarification raised G% and GSI compared to intact seeds. Intact and scarified seeds had 100% and 70% NS%, respectively, when not cryopreserved. Cryopreservation reduced NS% to 62% and 12.75%, respectively. The highest SL was observed in intact and non-cryopreserved seeds, with an average of 10.21 cm in height. However, the cryopreservation of intact seeds reduced SL by about 50%, and scarification led to a further reduction, either with (3.32 cm) or without (2.47 cm) cryopreservation. Seedlings from intact and non-cryopreserved seeds showed higher DM in relation to seedlings from cryopreserved seeds. The association of cryopreservation and scarification further reduced DM. The cryopreservation of intact seeds yielded 100% survival at the end of the acclimatization process. However, cryopreservation of scarified seeds reduced the survival percentage to 15%. Changes in color were observed for seeds scarified and subjected to cryopreservation. Thus, cryopreservation is considered an efficient technique for the conservation of intact H. acetosella seeds in the long term.


1982 ◽  
Vol 33 (6) ◽  
pp. 887 ◽  
Author(s):  
AP Hamblin ◽  
D Tennant ◽  
H Cochrane

In the fourth consecutive year of a long-term tillage trial in a loamy sand in Western Australia above- and below-ground growth of a wheat crop (cv. Gamenya) was monitored. The grain yield was nearly 20% greater in the crop sown after ploughing than in those crops sown by direct drilling. A similar trend had been noted in each preceding year. Cumulative water use was 15 and 9 mm less with zero and minimum tillage than with ploughing. The ploughed treatment had lower soil strengths, not only in the seedbed but also to 50 cm in the subsoil, until 8 weeks after seeding. These lower soil strengths coincided with more-rapid wetting of the subsoil under ploughing, and faster root extension rates. Dry matter production was significantly greater in the ploughed crop from the initial sampling date, and direct-drilled crops were not able to compensate in the later part of the season, despite using slightly more water during that period. The slower wetting of the profile under direct drilling was a persistent feature over several seasons in this soil type. It was considered responsible for the increased soil strength and slower root extension rates. The implications of direct-drilled sandy soils for crop productivity, and drainage control of recharge soils in saline catchments, are discussed.


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