Application of anhydrous ammonia or urea during the fallow period for winter cereals on the Darling Downs, Queensland .II. The recovery of 15N by wheat and sorghum in soil and plant at harvest

Soil Research ◽  
1992 ◽  
Vol 30 (5) ◽  
pp. 711 ◽  
Author(s):  
WM Strong ◽  
PG Saffigna ◽  
JE Cooper ◽  
AL Cogle

Three field experiments were conducted on the Darling Downs (Queensland) to evaluate fertilizer management practices such as application depth and addition of nitrification inhibitor (N-serve), for nitrogen (N) applied in the February-May fallow period for winter cereals. Anhydrous ammonia or urea was applied in February, March or May at two depths (7 or 17 cm), with or without N-serve. Soil fertilized in February generally had a lower mineral-N content at sowing than soil fertilized in May. Deeper application (17 cm) in February did not increase soil mineral-N content to 0.2 m depth in May but addition of N-serve did at one site where it appeared to slow the movement of mineral N into the subsoil (0.2-0.4 m). A companion experiment was conducted at each site in which 15N-enriched urea was applied to a small (1 m2) area at the centre of a 4 m2 fertilized plot. Effects of fertilizer placement and N-serve treatment, as were used in field experiments, were evaluated in terms of crop recovery of 15N and total 15N recovery in plant and soil at harvest. Recovery of 15N by wheat, sown at two sites in June, showed that neither fertilizer management practice, application depth nor N-serve affected 15N recovery. At only one site did wheat recover less February-applied N than May-applied N. N-serve had no effect on 15N recovery by sorghum sown in October, of N applied in February or May, but 15N recovery was increased by deeper fertilizer placement. Total recovery of 15N in soil and plant after wheat harvest was lower (-74%) for February-application than for May-application (>94%). Similarly, total 15N recovery after sorghum was lower the earlier the fertilizer was applied. Unrecovered 15N was presumed lost due to denitrification during periods of temporary waterlogging of surface soil. Use of N-serve with the fertilizer application had no effect in conserving 15N applied for wheat or sorghum. However, deeper (17 cm) placement of N than normal (7 cm) promoted higher total recoveries, and therefore reduced losses, of applied 15N at the three sites.

Soil Research ◽  
1992 ◽  
Vol 30 (5) ◽  
pp. 695 ◽  
Author(s):  
WM Strong ◽  
JE Cooper

Nine field experiments were conducted in 1978, 1981 and 1982 to evaluate applications of anhydrous ammonia (AA) or urea applied during the fallow period (January-May) for winter cereal crops. Following fertilizer application, soil was sampled using a stratified soil coring procedure to determine the rate of transformation of applied N to nitrate (nitrification), the quantity of N remaining in mineral forms (NH4+NO3 and NO2), and the movement of applied N into the subsoil. Nitrification of applied N was usually quite rapid in moist soil, particularly with early application (January, February or March when mean soil temperature was >20�C. Very similar rates of nitrification (0.6-4.7 kg N ha-1 day-1) were found for AA and urea applications in May 1982. Extreme drying of soil following N application reduced nitrification to a very low rate in May 1982 (0.6 kg N ha-1 day-1) and to an undetectable level in January 1981. In moist soil in February 1978, AA applied at 56 kg N ha-1 was nitrified completely after 11 days and the 112 kg N ha-1 rate was estimated to have nitrified completely in about 12 days. Also, AA applied to moist soil in May 1978 was estimated to have nitrified completely in about 28 and 42 days for 56 and 112 kg N ha-1 rates, respectively. Low recovery of early applied N as soil mineral N in June 1981 was associated with very heavy rain received during the latter part of the fallow period (March-May). Soil erosion on sloping sites and on a level site was a likely cause for the very low recovery (<47% that of a May application) of January-applied N, and some movement of mineral N below 0.2 m was also evident. Low recovery in fertilized soil (0.2 m) at the level sites was due to a large proportion of mineral N moving into the subsoil (below 0.9 m at one site). Also, prolonged periods of waterlogging during April probably promoted some loss of N due to denitrification, thus resulting in reduction in soil mineral N levels. Low recoveries of early applied N in mineral forms at the end of relatively drier fallows in 1978 and 1982 were also associated with soil saturating rainfall during the latter part of the fallow period. Where wheat crops responded to applied N, January or February applications were less effective than May applications to increase yield and N content of grain.


2002 ◽  
Vol 51 (1-2) ◽  
pp. 139-146 ◽  
Author(s):  
É. Bircsák ◽  
Tamás Németh

Long-term N fertilization experiments were established with identical treatments at two different growing areas in Hungary: one on a calcareous sandy soil (Őrbottyán) and the other on a calcareous chernozem soil (Nagyhörcsök). The aim was to create differences in mineral-N content in the soil profiles in order to determine their N supplying capacity and to establish whether the accumulated nitrate may be regarded as a supply index for crop production. The results showed that under certain environmental conditions N may accumulate in the soil profile in the form of nitrate, resulting from N fertilization in previous years, to such an extent that it must be taken into consideration when determining the fertilizer rates to be applied. This is important not only from the point of view of economical management and environment protection, but also for reaching better yield quality. The calculations can be reliably performed if they are based on the measurement and calibration of the soil's mineral-N content. The environmental importance of such calibration experiments is that by estimating the utilization of N from the mineral-N pool, the additional costs incurred due to over-fertilization can be eliminated, and at the same time the potential danger of NO 3 leaching to the groundwater can be reduced. Extrapolation of the experimental results to farm scale can lead to both economical and environmental achievements.


1986 ◽  
Vol 66 (3) ◽  
pp. 397-409 ◽  
Author(s):  
S. S. MALHI ◽  
M. NYBORG

Ten field experiments were conducted on cultivated soils in north-central Alberta to determine any change in mineral N content of soils during winter, and during early spring after the soils had thawed. Soil samples were taken periodically from fall to spring to a depth of 120 (or 90) cm and were analyzed for NH4-N and for NO3-N. Mineral N changes occurred primarily in the top 60 cm. Between fall and late winter, there was an increase of 48 kg N ha−1 of mineral N (range of 27–83) in the 60-cm depth of eight experiments set on stubble and the value increased only to 55 kg N ha−1 when the sampling depth was extended to 120 (or 90) cm. Considering only the values from soil samples taken when soils were frozen, the increase in mineral N was 31 kg N ha−1 (range of 14–54) in the 120-cm depth, and the average net mineral N accumulation was 0.35 kg N ha−1 d−1 (range of 0.26–0.43). There was a loss of mineral N during early spring of 44 kg N ha−1 (range of 18–71). The two experiments on summerfallow had more over-winter accumulation of mineral N and more loss in early spring compared to the stubble experiments. This study showed large increases in the mineral N content when the soil was frozen and large decreases in the early spring. The mechanism of increase in mineral N in frozen soil was not determined. The cause of the decrease in early spring was most likely denitrification, and was not leaching of nitrate. The results of the investigation may have implications for the time of soil test sampling and for the loss of native N from cultivated soils. Key words: Ammonium N, frozen soil, mineral N, nitrate N, early spring loss


1999 ◽  
Vol 39 (5) ◽  
pp. 587 ◽  
Author(s):  
J. A. Kirkegaard ◽  
P. M. Mele ◽  
G. N. Howe

The accumulation of mineral-nitrogen (N) in the top 10 cm of soil during the summer fallow was measured in 2 replicated field experiments following a range of crops including wheat, oats, canola, peas and lupins. At the first site, mineral-N was measured following harvest and in autumn before sowing subsequent crops across 3 seasons (1994–96). Crop residues were retained on the surface with intermittent grazing by sheep throughout the summer fallow and burnt before the autumn measurements. The smallest increase in mineral-N accumulation occurred following the cereals in all 3 seasons (mean increase 31 kg/ha). The highest accumulation of mineral-N in all seasons occurred following canola (mean 94 kg/ha), 3 times as much as that following cereals, and significantly higher than that after the legumes in 2 of the 3 seasons (mean 50 kg/ha). Differences in the amount, N content, or C : N ratio of the surface-retained crop residues are unlikely explanations for the observed differences in mineral-N accumulation. At a second site, measurements of the accumulation of mineral-N following canola and wheat were accompanied by measurements of populations of selected microorganisms involved with N cycling in soil. More mineral-N accumulated after canola than after wheat, however, populations of free-living, N-fixing bacteria, potential Azospirillim species and NH4+ oxidising bacteria were significantly lower following canola than following wheat, and populations of total bacteria and NO2− oxidising bacteria did not differ. These results suggest that greater mineral-N accumulation following canola does not result from a shift in those microbial populations which favour mineral-N accumulation, however, more detailed studies are required to resolve the exact cause of the differences. A possible explanation is that biocidal compounds released by canola roots during decay may cause a general ‘biofumigation’ and thereby result in a flush of mineral-N similar to that which accompanies chemical fumigation.


HortScience ◽  
2005 ◽  
Vol 40 (5) ◽  
pp. 1320-1323 ◽  
Author(s):  
Carmen Feller ◽  
Matthias Fink

The nitrogen requirement of broccoli (Brassica oleracea var. italica) ranges from 300 to 465 kg·ha–1. Recommendations for N fertilization are accordingly high. High fertilizer rates applied at planting result in a high soil mineral N content that remains high for weeks because the N requirement of the crop is low at early growth stages. Therefore, the risk of leaching is high for several weeks until the available N is finally taken up by the crop. Our study had two objectives: 1) to quantify yield responses to preplant fertilization, and 2) to test our hypothesis that the preplant fertilization rate could be reduced without yield losses by increasing the N content in the transplants and improving crop establishment. Field experiments were carried out on transplants with four levels of N content in dry matter (0.018 to 0.038 g·g–1 dry weight), which were tested in all combinations with four fertilization timings. All treatments received the same amount of N fertilizer (270 and 272 kg·ha–1 in 2001 and 2002, respectively), but with different rates of supply at the time of planting (0 to 90 kg·ha–1 N fertilizer plus 30 and 28 kg·ha–1 soil mineral N in 2001 and 2002, respectively). Total and marketable yields increased significantly with an increasing N supply at time of planting. In our experiments, in which topdressing was applied 25 days after planting, an N supply at planting of 80 to 118 kg·ha–1 was required to obtain maximum marketable yields. The N content in transplants had little effect on growth and yield, and there were no significant interactions between the N content in the transplant and fertilizer timing.


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1482
Author(s):  
Silvia Pampana ◽  
Alessandro Rossi ◽  
Iduna Arduini

Winter cereals are excellent candidates for biosolid application because their nitrogen (N) requirement is high, they are broadly cultivated, and their deep root system efficiently takes up mineral N. However, potential N leaching from BS application can occur in Mediterranean soils. A two-year study was conducted to determine how biosolids affect biomass and grain yield as well as N uptake and N leaching in barley (Hordeum vulgare L.), common wheat (Triticum aestivum L.), durum wheat (Triticum turgidum L. var. durum), and oat (Avena byzantina C. Koch). Cereals were fertilized at rates of 5, 10, and 15 Mg ha−1 dry weight (called B5, B10, and B15, respectively) of biosolids (BS). Mineral-fertilized (MF) and unfertilized (C) controls were included. Overall, results highlight that BS are valuable fertilizers for winter cereals as these showed higher yields with BS as compared to control. Nevertheless, whether 5 Mg ha−1 of biosolids could replace mineral fertilization still depended on the particular cereal due to the different yield physiology of the crops. Moreover, nitrate leaching from B5 was comparable to MF, and B15 increased the risk by less than 30 N-NO3 kg ha−1. We therefore concluded that with specific rate settings, biosolid application can sustain yields of winter cereals without significant additional N leaching as compared to MF.


Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 789
Author(s):  
Klára Kosová ◽  
Miroslav Klíma ◽  
Ilja Tom Prášil ◽  
Pavel Vítámvás

Low temperatures in the autumn induce enhanced expression/relative accumulation of several cold-inducible transcripts/proteins with protective functions from Late-embryogenesis-abundant (LEA) superfamily including dehydrins. Several studies dealing with plants grown under controlled conditions revealed a correlation (significant quantitative relationship) between dehydrin transcript/protein relative accumulation and plant frost tolerance. However, to apply these results in breeding, field experiments are necessary. The aim of the review is to provide a summary of the studies dealing with the relationships between plant acquired frost tolerance and COR/LEA transcripts/proteins relative accumulation in cereals grown in controlled and field conditions. The impacts of cold acclimation and vernalisation processes on the ability of winter-type Triticeae to accumulate COR/LEA proteins are discussed. The factors determining dehydrin relative accumulation under controlled cold acclimation treatments versus field trials during winter seasons are discussed. In conclusion, it can be stated that dehydrins could be used as suitable indicators of winter survival in field-grown winter cereals but only in plant prior to the fulfilment of vernalisation requirement.


Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 921
Author(s):  
Rania M. A. Nassar ◽  
Engy A. Seleem ◽  
Gianluca Caruso ◽  
Agnieszka Sekara ◽  
Magdi T. Abdelhamid

Egyptian henbane (Hyoscyamus muticus L.) plants are rich sources of alkaloids used in pharmaceutical products. Recently, rising efforts have been devoted to reducing mineral fertilizer supply, production cost, and environmental pollution via decreasing the doses of nitrogenous fertilizers and adopting biofertilizer farming systems. Two field experiments were conducted to examine the potential role of N fixing bacteria Azotobacter spp. and Azospirillum spp. on the growth, mineral status, tropane alkaloids, leaf anatomy, and seed yield of Egyptian henbane grown with different levels of mineral nitrogen fertilizer, i.e., 25%, 50%, and 100% of the recommended dose, equal to 30, 60, and 120 kg N ha−1. N fertilizer improved growth, mineral elements, tropane alkaloids, seed yield, and yield components of Egyptian henbane, which showed a gradually rising trend as the rate of N fertilizer increased. High doses of N fertilizer presumably elicited favorable changes in the anatomical structure of Egyptian henbane leaves. The application of 50% N dose plus N fixing bacteria affected Egyptian henbane trials similarly to 100% of recommended N dose. In conclusion, the N fixing bacteria proved to be a sustainable tool for a two-fold reduction in the recommended dose of mineral N fertilizer and the sustainable management of Egyptian henbane nutrition.


2000 ◽  
Vol 135 (4) ◽  
pp. 335-346 ◽  
Author(s):  
A. WILCOX ◽  
N. H. PERRY ◽  
N. D. BOATMAN ◽  
K. CHANEY

Yields of arable crops are commonly lower on the crop margins or headlands, but the nature of the relationship between yield and distance from the crop edge has not been clearly defined, nor have the reasons for lower marginal yields. Surveys of 40 winter wheat headlands were carried out in 2 years to determine how yield changed with distance, and what factors might influence this relationship. Two field experiments were also conducted over 3 years in winter cereal headlands, in which the effect of distance was measured under conservation headland and conventional (fully sprayed) management.Yields in the headland surveys varied from 0·8 to 10·2 t/ha. An inverse polynomial regression model was fitted to yield and weed data. Best fits were obtained by using separate parameters for each site. Adjusting yields to take account of weed dry matter improved the non-linear fit between yield and distance from crop edge. Field experiments provided similar results but the non-linear relationship was not as apparent.There was a negative relationship between soil compaction, as measured by a cone penetrometer, and yield in one field experiment, where soil density values were relatively constant. No relationship was found between pattern of nitrogen fertilizer application and yield. Conservation headland management resulted in lower yield at one experimental site, especially in the third year, but not at the other site. Where yields were affected, weed dry matter was higher in conservation headland plots than in fully sprayed plots.Although greater weed competition appears to account for at least part of the observed yield reductions on headlands, the role of other factors, particularly soil compaction, needs further study. Increased weed infestation may be an indirect result of reduced crop competition caused by other adverse conditions.


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