scholarly journals Sustaining productivity of a Vertosol at Warra, Queensland, with fertilisers, no-tillage or legumes. 8. Effect of duration of lucerne ley on soil nitrogen and water, wheat yield and protein

2004 ◽  
Vol 44 (10) ◽  
pp. 1013 ◽  
Author(s):  
R. C. Dalal ◽  
E. J. Weston ◽  
W. M. Strong ◽  
M. E. Probert ◽  
K. J. Lehane ◽  
...  
Keyword(s):  
Soil Water ◽  
Soil Nitrogen ◽  
Soil Profile ◽  
Phase 1 ◽  
Wheat Yield ◽  
Soil N ◽  
N Supply ◽  
Long Duration ◽  
Moisture Deficit ◽  
Fertiliser Application

Soil nitrogen (N) supply in the Vertosols of southern Queensland, Australia has steadily declined as a result of long-term cereal cropping without N fertiliser application or rotations with legumes. Nitrogen-fixing legumes such as lucerne may enhance soil N supply and therefore could be used in lucerne–wheat rotations. However, lucerne leys in this subtropical environment can create a soil moisture deficit, which may persist for a number of seasons. Therefore, we evaluated the effect of varying the duration of a lucerne ley (for up to 4 years) on soil N increase, N supply to wheat, soil water changes, wheat yields and wheat protein on a fertility-depleted Vertosol in a field experiment between 1989 and 1996 at Warra (26°47′S, 150°53′E), southern Queensland. The experiment consisted of a wheat–wheat rotation, and 8 treatments of lucerne leys starting in 1989 (phase 1) or 1990 (phase 2) for 1, 2, 3 or 4 years duration, followed by wheat cropping. Lucerne DM yield and N yield increased with increasing duration of lucerne leys. Soil N increased over time following 2 years of lucerne but there was no further significant increase after 3 or 4 years of lucerne ley. Soil nitrate concentrations increased significantly with all lucerne leys and moved progressively downward in the soil profile from 1992 to 1995. Soil water, especially at 0.9–1.2 m depth, remained significantly lower for the next 3 years after the termination of the 4-year lucerne ley than under continuous wheat. No significant increase in wheat yields was observed from 1992 to 1995, irrespective of the lucerne ley. However, wheat grain protein concentrations were significantly higher under lucerne–wheat than under wheat–wheat rotations for 3–5 years. The lucerne yield and soil water and nitrate-N concentrations were satisfactorily simulated with the APSIM model. Although significant N accretion occurred in the soil following lucerne leys, in drier seasons, recharge of the drier soil profile following long duration lucerne occurred after 3 years. Consequently, 3- and 4-year lucerne–wheat rotations resulted in more variable wheat yields than wheat–wheat rotations in this region. The remaining challenge in using lucerne–wheat rotations is balancing the N accretion benefits with plant-available water deficits, which are most likely to occur in the highly variable rainfall conditions of this region.

Sweet Clover Termination Effects on Weeds, Soil Water, Soil Nitrogen, and Succeeding Wheat Yield

2010 ◽  
Vol 102 (2) ◽  
pp. 634-641 ◽  
Author(s):  
Robert E. Blackshaw ◽  
Louis J. Molnar ◽  
James R. Moyer
Keyword(s):  
Soil Water ◽  
Soil Nitrogen ◽  
Wheat Yield ◽  
Sweet Clover

Validation of NBudget for estimating soil N supply in Australia's northern grains region in the absence of soil test data

Soil Research ◽  
2017 ◽  
Vol 55 (6) ◽  
pp. 590 ◽  
Author(s):  
David F. Herridge
Keyword(s):  
Soil Water ◽  
Organic N ◽  
Soil N ◽  
Limited Information ◽  
Available N ◽  
Support Tool ◽  
Grain Yields ◽  
N Supply ◽  
Nitrate N ◽  
Winter Crop

Effective management of fertiliser nitrogen (N) inputs by farmers will generally have beneficial productivity, economic and environmental consequences. The reality is that farmers may be unsure of plant-available N levels in cropping soils at sowing and make decisions about how much fertiliser N to apply with limited information about existing soil N supply. NBudget is a Microsoft (Armonk, NY, USA) Excel-based decision support tool developed primarily to assist farmers and/or advisors in Australia’s northern grains region manage N. NBudget estimates plant-available (nitrate) N at sowing; it also estimates sowing soil water, grain yields, fertiliser N requirements for cereals and oilseed crops and N2 fixation by legumes. NBudget does not rely on soil testing for nitrate-N, organic carbon or soil water content. Rather, the tool relies on precrop (fallow) rainfall data plus basic descriptions of soil texture and fertility, tillage practice and information about paddock use in the previous 2 years. Use is made of rule-of-thumb values and stand-alone or linked algorithms describing, among other things, rates of mineralisation of background soil organic N and fresh residue N. Winter and summer versions of NBudget cover the 10 major crops of the region: bread wheat, durum, barley, canola, chickpea and faba bean in the winter crop version; sorghum, sunflower, soybean and mung bean in the summer crop version. Validating the winter crop version of NBudget estimates of sowing soil nitrate-N against three independent datasets (n=65) indicated generally close agreement between measured and predicted values (y=0.91x+16.8; r2=0.78). A limitation of the tool is that it does not account for losses of N from waterlogged or flooded soils. Although NBudget also predicts grain yields and fertiliser N requirements for the coming season, potential users may simply factor predicted soil N supply into their fertiliser decisions, rather than rely on the output of the tool. Decisions about fertiliser N inputs are often complex and are based on several criteria, including attitudes to risk, history of fertiliser use and costs. The usefulness and likely longevity of NBudget would be enhanced by transforming the current Excel-based tool, currently available on request from the author, to a stand-alone app or web-based tool.

Relationship of the Illinois soil nitrogen test to spring wheat yield and response to fertilizer nitrogen

2008 ◽  
Vol 88 (5) ◽  
pp. 837-848 ◽  
Author(s):  
S J Steckler ◽  
D J Pennock ◽  
F L Walley
Keyword(s):  
Soil Nitrogen ◽  
Crop Yields ◽  
Wheat Yield ◽  
N Fertilizer ◽  
Yield Response ◽  
Regression Equations ◽  
Soil N ◽  
Fertilizer N ◽  
Available N ◽  
Nitrate N

The Illinois soil N test (ISNT) has been used to distinguish between soils that are responsive and non-responsive to fertilizer N in Illinois. We examined the suitability of this test, together with more traditional measures of soil fertility, including spring nitrate-N and soil organic carbon (SOC), for predicting yield and N fertilizer response of wheat (Triticum aestivum) on hummocky landscapes in Saskatchewan. The relationship between ISNT-N and wheat yield and fertilizer N response was assessed using data and soils previously collected for a variable-rate fertilizer study. Soils were re-analyzed for ISNT-N. Our goal was to determine if ISNT-N could be used to improve the prediction of crop yields. Although ISNT-N was correlated with both unfertilized wheat yield (r = 0.467, P = 0.01) and fertilizer N response (r = -0.671, P = 0.01) when data from all study sites were combined, correlations varied according to landscape position and site. Stronger correlations between nitrate-N and both unfertilized wheat yield (r = 0.721, P = 0.01) and fertilizer N response (r = -0.690, P = 0.01) indicated that ISNT-N offered no advantage over nitrate-N. Although both tests broadly discriminated between sites with high or low N fertility, few relationships were detected on a point-by-point basis within a field. Stepwise regression equations predicting yield and yield response did not include ISNT-N, due in part to the high degree of collinearity between ISNT-N and other variables such as SOC, suggesting that ISNT-N alone was not a key indicator of soil N supply. Key words: Illinois soil nitrogen test, potentially available N, soil N, fertilizer N recommendations

Effect of P fertilizer and precipitation on wheat under permanent beds in the absence of N fertilizer application

2022 ◽  
pp. 1-8
Author(s):  
A. Limon-Ortega ◽  
A. Baez-Perez
Keyword(s):  
Vegetation Index ◽  
Wheat Yield ◽  
Relative Yield ◽  
Fertilizer Application ◽  
N Fertilizer ◽  
Reproductive Stage ◽  
Soil N ◽  
Soil P ◽  
N Supply ◽  
P Application

Abstract Environmental conditions contribute to a large percentage of wheat yield variability. This phenomenon is particularly true in rainfed environments and non-responsive soils to N. However, the effect of P application on wheat is unknown in the absence of N fertilizer application. This study was conducted from 2012 to 2019 in permanent beds established in 2005. Treatments were arranged in a split-plot design and consisted of superimposing three P treatments (foliar, banded and broadcast application) plus a check (0P) within each one of four preceding N treatments (applied from 2005 to 2009). Foliar P generally showed a greater response than granular P treatments even though the soil tests high P (>30 mg/kg). Precipitation estimated for two different growth intervals explained through regression procedures the Years' effect. Seasonal precipitation (224–407 mm) explained variation of relative yield, N harvest index (NHI) and P agronomic efficiency (AE). Reproductive stage precipitation (48–210 mm) explained soil N supply. In dry years, foliar P application improved predicted relative yield 14% and AE 155 kg grain/kg P compared to granular P treatments. Similarly, soil N supply increased 15 kg/ha in dry moisture conditions during the reproductive stage. The NHI consistently improved over the crop seasons. This improvement was relatively larger for 0 kg N/ha. On average, NHI increased from about 0.57 to 0.72%. Normalized difference vegetation index (NDVI) readings at the booting growth stage were negatively associated with NHI. Foliar P in this non-responsive soil to N showed the potential to replace granular P sources. However, the omission of granular P needs to be further studied to estimate the long-term effect on the soil P test.

Modifying sexual expression of containerized jack pine by topping, altering soil nitrogen and water, and applying gibberellins

1994 ◽  
Vol 24 (5) ◽  
pp. 869-877 ◽  
Author(s):  
W.H. Fogal ◽  
S.J. Coleman ◽  
M.S. Wolynetz ◽  
H.O. Schooley ◽  
S.M. Lopushanski ◽  
...  
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Soil Nitrogen ◽  
Soil Water Potential ◽  
Jack Pine ◽  
Sexual Expression ◽  
Growth Responses ◽  
Tree Crown ◽  
N Supply ◽  
Water Potentials

The numbers of seed strobili and pollen strobilus clusters and the extent of branch terminal growth were determined on 6-year-old containerized jack pine (Pinusbanksiana Lamb.) trees following modification of the soil nitrogen (N) supply (NH4NO3 at 3, 100, or 300 mg N/L; NO3− at 100 mg N/L; or NH4+ at 100 mg N/L in a nutrient solution), soil water supply (soil water potentials above −20 kPa compared with potentials near −70 kPa), and tree crown size (intact trees outside polythene shelters and lightly versus severely topped trees under polythene shelters). These factors were tested with or without biweekly foliar applications of spray solutions containing 400 mg/L of GA4/7. Intact trees outside polythene shelters did not display sexual or growth responses to N or GA4/7 treatments. Seed strobilus production on topped trees under shelters was not influenced by the level of topping or N supply, but it was depressed by low soil moisture potentials and stimulated by GA4/7 with high or low soil water potentials. Pollen strobilus production was depressed by severe topping and by low soil water potential; it was stimulated by GA4/7 on lightly topped trees but not on severely topped trees and by a low (3 mg N/L) N supply. In the year after treatment, terminal growth of a branch from the 2-year-old nodal whorl was not influenced by nitrogen supply or by light topping but it was increased by severe topping; it was increased by GA4/7 treatment if soil water potential was high but not with low water potential; it was depressed by low soil water potential.

Effects of wildfire and topography on soil nitrogen availability in a boreal larch forest of northeastern China

2015 ◽  
Vol 24 (3) ◽  
pp. 433 ◽  
Author(s):  
Jian-jian Kong ◽  
Jian Yang ◽  
Haiyan Chu ◽  
Xingjia Xiang
Keyword(s):  
Soil Nitrogen ◽  
Northeastern China ◽  
Larch Forest ◽  
N Availability ◽  
N Mineralisation ◽  
Soil N ◽  
Inorganic N ◽  
Soil N Availability ◽  
N Supply ◽  
Burned Site

Both topography and wildfire can strongly affect soil nitrogen (N) availability. Although many studies have examined the individual effects of fire and topography on N, few have investigated their combined influences and relative importance. In this study, we measured soil extractable inorganic N concentrations, N mineralisation rates, and in situ soil inorganic N supply rates at 36 plots in three topographic positions (north-facing, south-facing and flat valley bottom) of burned and unburned sites in a boreal larch forest of northeastern China. Our data showed that wildfire significantly increased soil N availability, with mean soil extractable inorganic N concentrations, N mineralisation rates and N supply rates being 63, 310 and 270% higher in the burned site 1 year following fire. Additionally, soil N availability in the unburned site was significantly greater on the north-facing slope than on the south-facing slope, though this pattern was reversed at the burned site. Wildfire and topography together explained ~50% of the variance in soil N availability, with wildfire explaining three times more than topography. Our results demonstrate that wildfire and topography jointly affected spatial variations of soil N availability, and that wildfire decreased the influence of topography in the early successional stage of this boreal larch ecosystem.

Effects of deep ripping and liming on soil water deficits, sorptivity and penetrometer resistance

1987 ◽  
Vol 27 (5) ◽  
pp. 701 ◽  
Author(s):  
GR Steed ◽  
TG Reeves ◽  
ST Willatt
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Soil Profile ◽  
Wheat Yield ◽  
Major Effect ◽  
Water Extraction ◽  
Soil Resistance ◽  
Wet Season ◽  
Penetrometer Resistance ◽  
Yield Responses

A field experiment was conducted at Rutherglen, in north-eastern Victoria, to determine the effects of liming and deep ripping on soil water extraction by wheat, sorptivity of water into the soil profile and soil resistance to a penetrometer. The site was typical of many cropping paddocks in the region. In the unmodified state the top 20 cm of the soil profile was acid (pH 4.80) and there was a dense hardpan between 7.5 and 17.5 cm depth. Deep ripping increased water extraction by wheat by an average of 8 mm during a drought season (1982), but had no effect on water use in a wet season (1983). The major effect of ripping was to increase the water use in winter from below the ripped zone (40 cm) compared with the unripped treatment. Lime, either with or without ripping, had no significant effect on crop water extraction. Sorptivity, a measure of infiltration, was increased by ripping alone and by ripping plus lime. Soil resistance to a penetrometer was reduced by deep ripping; an effect which had persisted at least 30 months after the last ripping operation. Economic wheat yield responses were obtained by using deep ripping and liming to improve soil physical properties at this site.

Root biomass in the upper layer of the soil profile is related to the stomatal response of wheat as the soil dries

2016 ◽  
Vol 43 (1) ◽  
pp. 62 ◽  
Author(s):  
Renu Saradadevi ◽  
Helen Bramley ◽  
Jairo A. Palta ◽  
Everard Edwards ◽  
Kadambot H. M. Siddique
Keyword(s):  
Stomatal Conductance ◽  
Soil Water ◽  
Soil Profile ◽  
Root Biomass ◽  
Stomatal Closure ◽  
Wheat Yield ◽  
Grain Filling ◽  
Potential Yield ◽  
Aba Metabolism ◽  
Terminal Drought

Terminal drought is a common abiotic stress affecting wheat yield in Mediterranean-type environments. As terminal drought develops, top layers of the soil profile dry, exposing the upper part of the root system to soil water deficit while deeper roots can still access soil water. Since open stomata rapidly exhausts available soil water, reducing stomatal conductance to prolong availability of soil water during grain filling may improve wheat yields in water-limited environments. It was hypothesised that genotypes with more root biomass in the drying upper layer of the soil profile accumulate more abscisic acid in the leaf and initiate stomatal closure to regulate water use under terminal drought. The wheat cultivar Drysdale and the breeding line IGW-3262 were grown in pots horizontally split into two segments by a wax-coated layer that hydraulically isolated the top and bottom segments, but allowed roots to grow into the bottom segment. Terminal drought was induced from anthesis by withholding water from (i) the top segment only (DW) and (ii) the top and bottom segments (DD) while both segments in well-watered pots (WW) were maintained at 90% pot soil water capacity. Drysdale, initiated stomatal closure earlier than IGW-3262, possibly due to higher signal strength generated in its relatively larger proportion of roots in the drying top segment. The relationship between leaf ABA and stomatal conductance was strong in Drysdale but weak in IGW-3262. Analysis of ABA metabolites suggests possible differences in ABA metabolism between these two genotypes. A higher capability of deeper roots to extract available water is also important in reducing the gap between actual and potential yield.

scholarly journals Soil nitrogen dynamics in canola agroecosystems of eastern Canada

2021 ◽  
Author(s):  
Leanne Ejack ◽  
Bineeta Gurung ◽  
Philippe Seguin ◽  
Baoluo Ma ◽  
Joann K. Whalen
Keyword(s):  
Soil Nitrogen ◽  
N Uptake ◽  
Soil N ◽  
Fertilizer Management ◽  
Eastern Canada ◽  
Brassica Napus L ◽  
Site Specific ◽  
N Supply ◽  
Soil Nitrogen Dynamics ◽  
Soil N Pools

Canola (Brassica napus L.) is a nitrogen (N)-demanding crop, so tissue N analysis should be related to soil N supply. We evaluated canola N uptake in relation to soil N pools in plots receiving 0, 50, 100 and 150 kg N ha-1 from urea at three sites in eastern Canada in 2012. Soil N pools varied significantly at the rosette, flowering, pod filling and maturity stages, but responded less predictably to urea. Canola N uptake was inconsistently related to soil N pools and urea input. This confirms the importance of site-specific N fertilizer management when growing canola in eastern Canada.

Soil nitrogen supply to rice: crop sequence effects

1994 ◽  
Vol 34 (7) ◽  
pp. 987 ◽  
Author(s):  
HG Beecher ◽  
JA Thompson ◽  
PE Bacon ◽  
BW Dunn
Keyword(s):  
Soil Nitrogen ◽  
Nitrogen Supply ◽  
Rice Crop ◽  
Cereal Crops ◽  
Winter Cereal ◽  
Grain Yields ◽  
N Supply ◽  
Cropping Sequence ◽  
Fertiliser Application ◽  
Crop Sequence

The effect of cropping sequence on soil nitrogen (N) supply to a rice crop was investigated using an in situ incubation technique in a direct drill system on a red-brown earth soil in south-eastern Australia. The crop sequences were (i) a rice crop in each of the previous 4 summers, (ii) rice then 4 seasons of annual pasture (long pasture phase), (iii) rice, 2 winter cereal crops then 2 seasons of annual pasture (short pasture phase), and (iv) rice then 4 winter cereal crops. This study was undertaken in the fifth year of the crop sequence experiment, when all sequences had returned to rice. Within the rice crop, fertilised (160 kg N/ha) and unfertilised plots were established on the burnt stubble portion of the main crop sequence plots. Nitrogen uptake in unfertilised plots ranged from 79 kg N/ha in continuously cropped rice treatments to 165 kg N/ha in short pasture phase treatments. Application of 160 kg N/ha at permanent flood increased N uptake to 207 kg N/ha for the short pasture treatment. Crop biomass and tillering varied with cropping sequence and increased with fertiliser nitrogen application. Crop sequence had little effect on soil mineral N content during the growing season. However, total soil N mineralisation during the season varied with both crop sequence and fertiliser application. The continuous rice sequence mineralised 119 kg N/ha, whilst the long pasture phase sequence mineralised 246 kg N/ha. Fertiliser application increased mineralised N to 267 and 337 kg N/ha for continuous rice and short pasture phase treatments, respectively. Nitrogen mineralisation rate peaked (4 kg N/ha.day) some 40-50 days after permanent flood, coinciding with panicle initiation and the period of high N demand in the rice crop. Increased N availability after panicle initiation resulted in significantly higher grain yields. This work demonstrates that both the magnitude and timing of N supply affects the grain yield of the rice crop. Nitrogen supply is affected by the previous crop sequences. Practical implications are that pasture phase length of highly clover-dominant pastures could be reduced (from 4 to 2 years) and still provide similar contributions of N to succeeding rice crops; that continuous rice growing might achieve high yields similar to rice in rotation with legume pastures with the judicious application of fertiliser N; and that these N fertiliser applications may have to be quite high to achieve grain yields similar to rice in rotation with legume pastures.

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