Mineral nitrogen supply from pastures to cereals in three northern Victorian environments

2006 ◽  
Vol 46 (1) ◽  
pp. 59 ◽  
Author(s):  
R. H. Harris ◽  
M. J. Unkovich ◽  
J. Humphris

An experiment at 3 sites (Birchip, Elmore and Speed) in the northern Victorian cropping belt compared dry matter (DM) production of short-term (2 year) pastures and their contributions to soil mineral nitrogen (N) and subsequent wheat and barley production. The pastures included different varieties of subterranean clover, annual medic and lucerne, and these were compared with ryegrass-dominant pasture, which represented the experimental control. More productive legume pastures generally resulted in greater accumulation of soil mineral N at sowing of the following cereal at both Elmore and Speed; however, at Birchip, soil mineral N remained high under all treatments. At Elmore and Speed, significant (P<0.10) positive relationships were observed between available N at sowing and subsequent wheat and barley production. Cereal grain yield at Birchip was not associated with available N at sowing. The quantities of soil mineral N available at sowing (152 kg/ha) of the cereals were in excess of crop demand at Birchip. At Elmore, the soil mineral N supply (83 kg/ha) was below that required for wheat and barley to reach their water-limited potential yield (20 kg grain/mm of growing season rainfall). However, at Speed, the supply of soil mineral N (63 kg/ha) was sufficient to achieve the water-limited potential grain yield and to produce malting-grade barley, but not sufficient to elevate wheat grain protein concentrations above 11.5%. In environments with low soil N levels, the amount of residual N following short-term pastures increased the availability of N to following cereals. Whether this is sufficient to satisfy subsequent crop demand is largely determined by water availability in the year of cropping. In cases where available N is already high, short-term pasture phases may have little effect on increasing crop production.

2001 ◽  
Vol 10 (3) ◽  
pp. 197-208 ◽  
Author(s):  
H. KÄNKÄNEN ◽  
C. ERIKSSON ◽  
M. RÄKKÖLÄINEN

Cover crops can be used to reduce leaching and erosion, introduce variability into crop rotation and fix nitrogen (N) for use by the main crops. In Finland, undersowing is a suitable method for establishing cover crops in cereal cropping. The effect of annual undersowing on cereal grain yield and soil mineral N content in spring was studied at two sites. Red clover (Trifolium pratense L.), white clover (Trifolium repens L.), a mixture of red clover and meadow fescue (Festuca pratensis Huds.), and westerwold ryegrass (Lolium multiflorum Lam. var. westerwoldicum) were undersown in spring cereals in the same plots in six successive seasons, and their effects on cereal yield were estimated. Annual undersowing with clovers increased, and undersowing with westerwold ryegrass decreased cereal grain yields. The grain yield was only slightly lower with a mixture of red clover and meadow fescue than with red clover alone. Westerwold ryegrass did not affect soil mineral N content in spring and the increase attributable to clovers was small. The mixture of red clover and meadow fescue affected similarly to pure red clover. Soil fertility was not notably improved during six years of undersowing according to grain yield two years later.


1986 ◽  
Vol 26 (3) ◽  
pp. 347 ◽  
Author(s):  
WM Strong ◽  
J Harbison ◽  
RGH Nielsen ◽  
BD Hall ◽  
EK Best

Available soil mineral nitrogen (N) was determined in a Darling Downs clay at intervals of 4-6 weeks throughout summer and autumn after harvest of two cereals (wheat and oats), two oilseeds (rapeseed and linseed), and four grain legumes (chickpea, fieldpea, lupin and lathyrus). Soil mineral N (0-1.2 m) at 40,68, 107, 150 and 185 days after harvest was affected (P < 0.05) by the prior crop. At 40 days it was generally higher following grain legumes (34-76 kg/ha N) than following oilseeds or cereals (16-30 kg/ha N). Net increase during the next 145 days was in the order of cereals (2 1-27 kg/ha N) < oilseeds (40 kg/ha N) <grain legumes (53-85 kg/ha N). These differences are partly accounted for by differences in the quantities of N removed in the grain of these crops. However, a large quantity of mineral N accumulated following lupin even though a large quantity (80 kg/ha) was removed in the grain.


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%).


1987 ◽  
Vol 27 (2) ◽  
pp. 295 ◽  
Author(s):  
WM Strong ◽  
RC Dalal ◽  
JE Cooper ◽  
PG Saffigna

Mineralisation and availability of residual fertiliser nitrogen (N) was studied in pots during December-October with and without the addition of straw (0-7.5 t/ha) on a Darling Downs black earth previously cropped with wheat. Soil (0-0.2 m) and straw were collected from field plots in which wheat was grown previously with supplementary irrigation and fertiliser N applied at 0, 100, 200, 300 or 400 kg/ha. At the end of the fallow, in June, there was a net increase in soil mineral N of between 0.7 and 11.1 mg/kg where fertiliser was applied to the preceding crop. The increase represented between 2 and 9% of the original N application and was larger with increasing N application rate and smaller with increasing rate of straw addition. Straw addition caused a substantial decrease in mineral N which was still evident in June and October, 162 and 305 days respectively following straw addition. Soil mineral N decreased linearly at the rate of 5 kg N/t of straw added up to 7.5 t/ha. The net effect of prior N applications on the quantity of N available to wheat plants was equivalent to 10-23% of the quantity of N applied to the preceding crop in the absence of straw and only 4% in the presence of straw. Residual effects of prior N applications on the quantity of N available for wheat plants was generally greater than was evident as soil mineral N in June. During crop growth, additional available N may have been released from the microbial soil N pool, especially where 200 or 400 kg/ha of N had been applied. Straw addition resulted in more microbial biomass throughout the fallow. The larger microbial N pool, however, contained less N than that immobilised due to straw addition. Thus, regardless of prior N application, less N was available to wheat plants in the presence than in the absence of straw of preceding wheat crops.


2013 ◽  
Vol 93 (3) ◽  
pp. 369-378 ◽  
Author(s):  
E. W. Bork ◽  
B. D. Lambert ◽  
S. Banerjee ◽  
L. J. Blonski

Bork, E. W., Lambert, B. D., Banerjee, S. and Blonski, L. J. 2013. Soil mineral nitrogen responses following liquid hog manure application to semiarid forage lands. Can. J. Soil Sci. 93: 369–378. Expansion of intensive livestock operations into semiarid regions lacking cultivated lands requires consideration of perennial forages for the efficient and sustainable disposal of manure. Little information exists on the nutrient dynamics associated with the application of manure to these areas. We examined soil mineral nitrogen (N) responses in four sites of the mixed-grass prairie, including two native grasslands and two introduced pastures, following different seasons (fall vs. spring), methods (dribble broadcast vs. coulter injected) and rates of liquid hog manure application (9.4, 18.8, 37.5, 75 and 150 kg ha−1available N). Soil mineral N, including NO3-N, NH4-N and total mineral N, were assessed after application but prior to plant growth in April 1999, and again one growing season later in April 2000. Initial soil N did not vary with season of application. Soil mineral N predictably increased with application rate, but only in the upper soil profile (0–20 cm). Decreases in soil mineral N after one growing season in all treatments highlighted the ability of these perennial forage lands to immobilize large amounts of soil N, a significant portion of which was related to N uptake by vegetation. Compared with broadcast application, manure injection led to 35% greater soil mineral N (both NO3and NH4) prior to plant growth, a response that persisted 1 yr later (+12%), thus demonstrating the N conserved benefits of manure incorporation. Overall, increases in soil mineral N within these forage lands appeared to be relatively short-term in nature, largely depleting over the course of a single growing season, suggesting one-time liquid hog manure application at low to moderate rates may be sustainable in this region of the mixed-grass prairie.


2007 ◽  
Vol 87 (4) ◽  
pp. 369-381 ◽  
Author(s):  
H. Dadfar ◽  
B D Kay ◽  
R. Pararajasingham ◽  
R S Dharmakeerthi ◽  
E G Beauchamp

A model that accurately simulates the seasonal variation in nitrogen (N) dynamics may represent an important additional tool in N management. The objectives of this study were to evaluate whether seasonal changes in the amount of N that becomes available to a maize crop in a variable landscape can be simulated with LEACHMN and, in particular, to assess the potential value of LEACHMN in estimating N available at the time of the presidedress soil nitrate test (PSNT). Soil mineral N (SMN) and shoot N were measured biweekly over seven growing seasons in corn (Zea Mays L.) grown under conventional tillage in a variable landscape in Southern Ontario, Canada. The model was calibrated using data from 2002 and 2003 from each of five positions in the landscape and then evaluated using data from the 1997–2001 growing seasons. Although the model under-estimated SMN and over-estimated shoot N, the model was more successful in simulating the sum, defined as plant available N (PAN). Simulations of PAN were best at the summit and shoulder positions. The agreement between measured and simulated PAN were poorest early in the season. Although the accuracy of PAN simulations late in the growing season indicates this model has potential value in N management decisions, the errors in simulating SMN early in the season suggest adjustments are required before it can be used, along with other tools, as a substitute for the PSNT in cool humid environments. Key words: Soil mineral N, Plant available N, variable landscapes, LEACHMN


Soil Research ◽  
2019 ◽  
Vol 57 (8) ◽  
pp. 859 ◽  
Author(s):  
G. D. Schwenke ◽  
B. M. Haigh

Most soil nitrous oxide (N2O) emissions from rain-fed grain sorghum grown on sub-tropical Vertosols in north-west New South Wales, Australia, occur between fertiliser nitrogen (N) application at sowing and booting growth stage. At three experiments, we investigated the potential for deferring some (split-N) or all (delayed) fertiliser N until booting to mitigate N2O produced without compromising optimum crop yields. N products included urea, 3,4-dimethyl pyrazole phosphate (DMPP)-urea, polymer-coated urea (PCU) and N-(n-butyl)thiophosphoric triamide (NBPT)-urea. For a fourth experiment, the N fertiliser rate was varied according to pre-sowing soil mineral N stocks left by different previous crops. All experiments incorporated 15N mini-plots to determine whether delayed or split-N affected crop N uptake or residual soil N. Compared to urea applied at-sowing, delayed applications of urea, DMPP-urea or NBPT-urea at booting reduced the N2O emission factor (EF, percentage of applied N emitted) by 67–81%. Crop N uptake, grain yield and protein tended to be lower with delayed N than N at-sowing due to dry mid-season conditions. Much of the unused N remained in the soil at harvest. Split-N (33% sowing:67% booting) using urea, reduced EF by 59% compared to at-sowing urea, but maintained crop N uptake, grain yield and protein. Using DMPP-urea or PCU for the at-sowing portion of the split reduced EF by 84–86%. Grain yield was maintained using PCU, but was lower with DMPP-urea, which had more N in vegetative biomass. Using NBPT-urea for the in-crop portion of the split did not affect N2O emissions or crop productivity. Nitrogen budgeting to account for high pre-sowing soil mineral N nullified urea-induced N2O emissions. An N-budgeted, split-N strategy using urea offers the best balance between N2O mitigation, grain productivity and provision of a soil mineral N buffer against dry mid-season conditions. Split-N using DMPP-urea or PCU further enhanced N2O mitigation but there was no yield response to justify the extra expense.


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