scholarly journals Predicting nitrogen requirement in perennial ryegrass seed crops

2010 ◽  
Vol 14 ◽  
pp. 59-65
Author(s):  
M.P. Rolston ◽  
B.L. Mccloy ◽  
R.J. Chynoweth

Results from 17 nitrogen (N) rate response trials using current best management including the plant growth regulator trinexapac-ethyl (Moddus) were used to predict optimum applied N rates for perennial ryegrass. The average optimum applied N rate was 145 kg/ha. A simple model using late winter soil mineral N (0-30 cm) and a total N requirement (mineral N + applied N) of 185 kg N/ha is recommended for growers to predict the applied spring N rate. Keywords: nitrogen, optimum rate, Lolium perenne, seed yield

1988 ◽  
Vol 36 (4) ◽  
pp. 375-385
Author(s):  
W.J.M. Meijer ◽  
S. Vreeke

The relationship between the level of soil mineral N present in early spring and the economically optimum application rate of N fertilizer was investigated in field experiments in 1978-84 at 4 locations in the Netherlands with Lolium perenne, Poa pratensis and Festuca rubra. Spring dressings, as split and single applications, of 30-210 kg N/ha and autumn dressings of 0-90 kg N/ha were used. The optimum spring rates were linearly related to mineral N in the 0-90 cm soil layers in L. perenne. No such relationship existed for the other species. The economically optimum spring N rates were 110 and 84 kg/ha, and yields were highest with autumn N dressings of 60 and 30 kg/ha for P. pratensis and F. rubra, resp. Autumn dressing had no effect on L. perenne if the spring dressing was near or above the optimum. A split spring dressing produced greater vegetative regrowth and reduced yields. Seed yield responses to fertilization were related to number of inflorescences produced rather than weight of seed per inflorescence. (Abstract retrieved from CAB Abstracts by CABI’s permission)


2021 ◽  
Author(s):  
Jie Luo ◽  
Lukas Beule ◽  
Guodong Shao ◽  
Edzo Veldkamp ◽  
Marife D. Corre

<p>Monoculture croplands are considered as major sources of the greenhouse gas, nitrous oxide (N<sub>2</sub>O). The conversion of monoculture croplands to agroforestry systems, e.g., integrating trees within croplands, is an essential climate-smart management system through extra C sequestration and can potentially mitigate N<sub>2</sub>O emissions. So far, no study has systematically compared gross rates of N<sub>2</sub>O emission and uptake between cropland agroforestry and monoculture. In this study, we used an in-situ <sup>15</sup>N<sub>2</sub>O pool dilution technique to simultaneously measure gross N<sub>2</sub>O emission and uptake over two consecutive growing seasons (2018 - 2019) at three sites in Germany: two sites were on Phaeozem and Cambisol soils with each site having a pair of cropland agroforestry and monoculture systems, and an additional site with only monoculture on an Arenosol soil prone to high nitrate leaching. Our results showed that cropland agroforestry had lower gross N<sub>2</sub>O emissions and higher gross N<sub>2</sub>O uptake than in monoculture at the site with Phaeozem soil (P ≤ 0.018 – 0.025) and did not differ in gross N<sub>2</sub>O emissions and uptake with cropland monoculture at the site with Cambisol soil (P ≥ 0.36). Gross N<sub>2</sub>O emissions were positively correlated with soil mineral N and heterotrophic respiration which, in turn, were correlated with soil temperature, and with water-filled pore space (WFPS) (r = 0.24 ‒ 0.54, P < 0.01). Gross N<sub>2</sub>O emissions were also negatively correlated with nosZ clade I gene abundance (involved in N<sub>2</sub>O-to-N<sub>2</sub> reduction, r = -0.20, P < 0.05). These findings showed that across sites and management systems changes in gross N<sub>2</sub>O emissions were driven by changes in substrate availability and aeration condition (i.e., soil mineral N, C availability, and WFPS), which also influenced denitrification gene abundance. The strong regression values between gross N<sub>2</sub>O emissions and net N<sub>2</sub>O emissions (R<sup>2 </sup>≥ 0.96, P < 0.001) indicated that gross N<sub>2</sub>O emissions largely drove net soil N<sub>2</sub>O emissions. Across sites and management systems, annual soil gross N<sub>2</sub>O emissions and uptake were controlled by clay contents which, in turn, correlated with indices of soil fertility (i.e., effective cation exchange capacity, total N, and C/N ratio) (Spearman rank’s rho = -0.76 – 0.86, P ≤ 0.05). The lower gross N<sub>2</sub>O emissions from the agroforestry tree rows at two sites indicated the potential of agroforestry in reducing soil N<sub>2</sub>O emissions, supporting the need for temperate cropland agroforestry to be considered in greenhouse gas mitigation policies.</p>


1999 ◽  
Vol 133 (3) ◽  
pp. 263-274 ◽  
Author(s):  
J. VOS

In four field experiments, the effects of single nitrogen (N) applications at planting on yield and nitrogen uptake of potato (Solanum tuberosum L.) was compared with two or three split applications. The total amount of N applied was an experimental factor in three of the experiments. In two experiments, sequential observations were made during the growing season. Generally, splitting applications (up to 58 days after emergence) did not affect dry matter (DM) yield at maturity and tended to result in slightly lower DM concentration of tubers, whereas it slightly improved the utilization of nitrogen. Maximum haulm dry weight and N content were lower when less nitrogen was applied during the first 50 days after emergence (DAE). The crops absorbed little extra nitrogen after 60 DAE (except when three applications were given). Soil mineral N (0–60 cm) during the first month reflected the pattern of N application with values up to 27 g/m2 N. After 60 DAE, soil mineral N was always around 2–5 g/m2. The efficiency of N utilization, i.e. the ratio of the N content of the crop to total N available (initial soil mineral N+deposition+net mineralization) was 0·45 for unfertilized controls. The utilization of fertilizer N (i.e. the apparent N recovery) was generally somewhat improved by split applications, but declined with the total amount of N applied (range 0·48–0·72). N utilization and its complement, possible N loss, were similar for both experiments with sequential observations. Separate analysis of the movement of Br− indicated that some nitrate can be washed below 60 cm soil depth due to dispersion during rainfall. The current study showed that the time when N application can be adjusted to meet estimated requirements extends to (at least) 60 days after emergence. That period of time can be exploited to match the N application to the actual crop requirement as it changes during that period.


2008 ◽  
Vol 23 (03) ◽  
pp. 250-259 ◽  
Author(s):  
Derek H. Lynch ◽  
Zhiming Zheng ◽  
Bernie J. Zebarth ◽  
Ralph C. Martin

AbstractThe market for certified organic potatoes in Canada is growing rapidly, but the productivity and dynamics of soil N under commercial organic potato systems remain largely unknown. This study examined, at two sites in Atlantic Canada (Winslow, PEI, and Brookside, NS), the impacts of organic amendments on Shepody potato yield, quality and soil mineral nitrogen dynamics under organic management. Treatments included a commercial hog manure–sawdust compost (CP) and pelletized poultry manure (NW) applied at 300 and 600 kg total N ha−1, plus an un-amended control (CT). Wireworm damage reduced plant stands at Brookside in 2003 and those results are not presented. Relatively high tuber yields (~30 Mg ha−1) and crop N uptake (112 kg N ha−1) were achieved for un-amended soil in those site-years (Winslow 2003 and 2004) when soil moisture was non-limiting. Compost resulted in higher total yields than CT in one of three site-years. Apparent recovery of N from CP was negligible; therefore CP yield benefits were attributed to factors other than N availability. At Winslow, NW300, but not NW600, significantly increased total and marketable yields by an average of 5.8 and 7.0 Mg ha−1. Plant available N averaged 39 and 33% for NW300 and NW600, respectively. Soil (0–30 cm) NO3−-N at harvest was low (<25 kg N ha−1) for CT and CP, but increased substantially both in season and at harvest (61–141 kg N ha−1) when NW was applied. Most leaching losses of NO3−-N occur between seasons and excessive levels of residual soil NO3-N at harvest, as obtained for NW600, must be avoided. Given current premiums for certified organic potatoes, improving yields through application of amendments supplying moderate rates of N or organic matter appears warranted.


2002 ◽  
Vol 139 (2) ◽  
pp. 115-127 ◽  
Author(s):  
MARTYN SILGRAM ◽  
BRIAN J. CHAMBERS

The effects of straw incorporation (early and late cultivation) and straw burning were contrasted in a split-plot study examining the impact of long-term straw residue management, and six fertilizer nitrogen (N) rates on soil mineral nitrogen, crop fertilizer N requirements and nitrate leaching losses. The experiments ran from 1984 to 1997 on light-textured soils at ADAS Gleadthorpe (Nottinghamshire, UK) and Morley Research Centre (Norfolk, UK).Soil incorporation of the straw residues returned an estimated 633 kg N/ha at Gleadthorpe and 429 kg N/ha at Morley on the treatment receiving 150 kg/ha per year fertilizer N since 1984. Straw disposal method had no consistent effect on grain and straw yields, crop N uptake, or optimal fertilizer N rates. In every year there was a positive response (P<0·001) to fertilizer N in straw/grain yields, N contents and crop N offtakes at both sites. Nitrate leaching losses were slightly reduced by less than 10 kg N/ha where straw residues had been incorporated, while fertilizer N additions increased nitrate leached at both sites.At both sites there was a consistent effect (P<0·001) of straw disposal method on autumn soil mineral N, with values following the pattern burn>early incorporate>late plough. The incorporation of straw residues induced temporary N immobilization compared with the treatment where straw was burnt, while the earlier timing of tillage on the incorporate treatment resulted in slightly more mineral N compared with the later ploughed treatment. Fertilizer N rate increased (P<0·001) soil mineral nitrogen at both sites. At Morley, there was more organic carbon in the plough layer where straw had been incorporated (mean 1·09 g/100 g) rather than burnt (mean 0·89 g/100 g), and a strong positive relationship between organic carbon and fertilizer N rate (r2=93·2%, P<0·01). There was a detectable effect of fertilizer N on readily mineralizable N in the plough layer at both Gleadthorpe (P<0·001) and Morley (P<0·05). At Morley, there was a consistent trend (P=0·06) for readily mineralizable N to be higher where straw had been incorporated rather than burnt, indicating that ploughing-in residues may contribute to soil nitrogen supply over the longer term.


2008 ◽  
Vol 88 (2) ◽  
pp. 175-187 ◽  
Author(s):  
Philippe Rochette ◽  
Denis A Angers ◽  
Martin H Chantigny ◽  
Bernard Gagnon ◽  
Normand Bertrand

Manure is known to increase soil N2O emissions by stimulating nitrification and denitrification processes. Our objective was to compare soil-surface N2O emissions following the application of liquid and solid dairy cattle manures to a loamy and a clay soil cropped to silage maize. Manures were applied in 2 consecutive years at rates equivalent to 150 kg total N ha-1 and compared with a control treatment receiving an equivalent rate of synthetic N. Soil-surface N2O fluxes, soil temperature, and soil water, nitrate and ammonium contents were monitored weekly in manured and control plots. From 60 to 90% of seasonal N2O emissions occurred during the first 40 d following manure and synthetic fertilizer applications, indicating that outside that period one or several factors limited N2O emissions. The period of higher emissions following manure and fertilizer application corresponded with the period when soil mineral N contents were highest (up to 17 g NO3−-N m-2) and water-filled pore space (WFPS) was greater than 0.5 m3 m-3. The absence of significant N2O fluxes later in the growing season despite high WFPS levels indicated that the stimulating effect of organic and synthetic N additions on soil N2O production was relatively short-lived. Fertilization of silage maize with dairy cattle manure resulted in greater or equal N2O emissions than with synthetic N. This was observed despite lower overall soil mineral N contents in the manured plots, indicating that other factors affected by manure, possibly additional C substrates and enhanced soil respiration, resulted in greater denitrification and N2O production. Silage maize yields in the manured soils were lower than those receiving synthetic N, indicating that the N2O emissions per kilogram of harvested biomass were greater for manures than for synthetic N. Our results also suggest that the main source of N2O was nitrification in the loam and denitrification in the clay soil. There was no clear difference in N2O emissions between liquid and solid manures. The variable effects of liquid and solid manure addition reported in the literature on soil N2O emissions likely result from the variable composition of the manures themselves as well as from interactions with other factors such as soil environment and farming practices. A better characterization of the availability of manure C and N is required to assess the impact of manure application on soil N2O emissions under field conditions. Key words: Greenhouse gases, N2O, maize, manure


Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 468
Author(s):  
Anastasios Gatsios ◽  
Georgia Ntatsi ◽  
Luisella Celi ◽  
Daniel Said-Pullicino ◽  
Anastasia Tampakaki ◽  
...  

An organic greenhouse crop of tomato was established in February following cultivation of cowpea (CP) or common bean (CB) for green pod production, or faba bean (FB) for green manuring. The vegetative residues of CP and CB were incorporated to the soil together with farmyard manure (FYM), prior to establishing the tomato crop. The FB plants were incorporated to the soil at anthesis together with either FYM or composted olive-mill waste (CO). Green manuring with FB resulted in higher soil mineral N levels during the subsequent tomato crop and higher tomato fruit yield when combined with FYM, compared to compost. The level of soil mineral N was the main restrictive factor for yield in organic greenhouse tomato. FB for green manuring as preceding crop to tomato increased significantly the level of soil mineral N and tomato yield compared to CB or CP aiming to produce green pods. The lowest tomato yield was obtained when the preceding crop was CB cultivated for green pod production. The soil mineral N was significantly higher when FYM was applied as base dressing compared with CO, despite the higher total N concentration in CO, pointing to slower mineralization rates of CO during tomato cultivation.


1999 ◽  
Vol 8 (4-5) ◽  
pp. 423-440 ◽  
Author(s):  
L. PIETOLA ◽  
R. TANNI ◽  
P. ELONEN

The role of plant growth regulators (PGR) in nitrogen (N) fertilization of spring wheat and oats (CCC), fodder barley (etephon/mepiquat) and oilseed rape (etephone) in crop rotation was studied in 1993–1996 on loamy clay soil. Carry over effect of the N fertilization rates (0–180 kg ha-1 ) was evaluated in 1997. N fertilization rate for the best grain/seed yield (120–150 kg ha-1 ) was not affected by PGRs. The seed and N yields of oilseed rape were improved most frequently by recommended use of PGR. The yields of oats were increased in 1995–96. Even though PGR effectively shortened the plant height of spring wheat, the grain yield increased only in 1995. N yield of wheat grains was not increased. Response of fodder barley to PGR was insignificant or even negative in 1995. The data suggest that PGRs may decrease some N leaching at high N rates by improving N uptake by grain/seeds, if the yield is improved. The carryover study showed that in soils with no N fertilization, as well as in soils of high N rates, N uptake was higher than in soils with moderate N fertilization (60–90 kg ha-1 ), independent of PGRs. According to soil mineral N contents, N leaching risk is significant (15–35 kg ha-1 ) only after dry and warm late seasons. After a favourable season of high yields, the N rates did not significantly affect soil mineral N contents. ;


Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2307
Author(s):  
Anna Nogalska ◽  
Aleksandra Załuszniewska

A long-term (six year) field experiment was conducted in Poland to evaluate the effect of meat and bone meal (MBM), applied without or with mineral nitrogen (N) fertilizer, on crop yields, N content and uptake by plants, and soil mineral N balance. Five treatments were compared: MBM applied at 1.0, 1.5, and 2.0 Mg ha−1, inorganic NPK, and zero-fert check. Mineral N accounted for 100% of the total N rate (158 kg ha−1) in the NPK treatment and 50%, 25%, and 0% in MBM treatments. The yield of silage maize supplied with MBM was comparable with that of plants fertilized with NPK at 74 Mg ha−1 herbage (30% DM) over two years on average. The yields of winter wheat and winter oilseed rape were highest in the NPK treatment (8.9 Mg ha−1 grain and 3.14 Mg ha−1 seeds on average). The addition of 25% and 50% of mineral N to MBM had no influence on the yields of the tested crops. The N content of plants fertilized with MBM was satisfactory (higher than in the zero-fert treatment), and considerable differences were found between years of the study within crop species. Soil mineral N content was determined by N uptake by plants rather than the proportion of mineral N in the total N rate. Nitrogen utilization by plants was highest in the NPK treatment (58%) and in the treatment where mineral N accounted for 50% of the total N rate (48%).


1983 ◽  
Vol 19 (1) ◽  
pp. 91-101 ◽  
Author(s):  
D. M. Oosterhuis ◽  
J. Chipamaunga ◽  
G. C. Bate

SUMMARYThree levels of nitrogen (N) were applied to cotton grown in irrigated field trials at two locations in Zimbabwe in 1978. Dry matter (DM) production, total uptake and distribution of N among vegetative and reproductive components, and soil mineral-N contents were recorded about every 14 days. About 60% of total DM was produced, and 40% of total N taken up, between 10 and 16 weeks after sowing. Most N was present in vegetative parts, particularly leaves and branches, during early growth but, later, it accumulated in buds, flowers and bolls. At maturity, seeds and lint contained 42% of total above-ground plant N. N concentrations were similar in sympodial and mainstem leaves, petioles and branches. Inorganic N applied at sowing had little effect on plant N, but when given after 10 weeks it increased the N content of leaves, stems, branches, petioles and bolls.


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