Impact of irrigation management on paddy soil N supply and depth distribution of abiotic drivers

Although increasing tropospheric ozone (O3) concentrations as well as precursor NO2 emissions and N deposition have been observed, the combination of their effects on deciduous trees is little understood. We therefore examined the growth and leaf injury response of a model tree (Populus ×euramericana (Dode) Guinier cuttings exposed before flush and until they reached a height of more than 1 m) to low and high soil N supply (105 or 315 mg N•L−1 substrate volume), to filtered air, and to filtered air with NO2 (sinusoidal daily course with a mean of 100 nL•L−1), with O3 (60 nL•L−1), or with a combination of both in climate-controlled chambers. High soil N increased total plant dry weight, leaf area, and xylem radius in plants fumigated with or without added NO2 or O3. The number of leaves increased with high soil N independent of added NO2. The stomatal density was influenced by soil N and by fumigations, but the appearance of leaf injury symptoms, leaf loss, specific leaf weight, and bark radius were not modified by the soil N regimes. NO2 alone, though applied in a sixfold ambient concentration, did not significantly increase plant growth. NO2 and O3 alone had opposite effects on specific leaf dry weight, stomatal density, and in the high fertilization regime, on the bark radius. The decrease in specific leaf dry weight and the appearance of early leaf symptoms were enhanced by NO2 added to O3. Visible leaf injury caused by O3 increased in parallel with microscopic changes in mesophyll cell walls, in the starch and protein patterns of mesophyll cells, in the bark cell content, and in the phloem sieve pores. NO2 enhanced the negative effect of O3 rather than compensated for a low soil N supply.

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

Soil Research ◽

10.1071/sr16336 ◽

2017 ◽

Vol 55 (6) ◽

pp. 590 ◽

Cited By ~ 4

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.

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Quantifying the effect of soil organic matter on indigenous soil N supply and wheat productivity in semiarid sub-tropical India

Nutrient Cycling in Agroecosystems ◽

10.1007/s10705-007-9100-z ◽

2007 ◽

Vol 79 (2) ◽

pp. 103-112 ◽

Cited By ~ 26

Author(s):

D. K. Benbi ◽

Milap Chand

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Soil N ◽

N Supply

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Crop Mass and N Status as Prerequisite Covariables for Unraveling Nitrogen Use Efficiency across Genotype-by-Environment-by-Management Scenarios: A Review

Plants ◽

10.3390/plants9101309 ◽

2020 ◽

Vol 9 (10) ◽

pp. 1309 ◽

Cited By ~ 2

Author(s):

Gilles Lemaire ◽

Ignacio Ciampitti

Keyword(s):

Growth Rate ◽

Plant Growth ◽

Nitrogen Use Efficiency ◽

Soil N ◽

Nitrogen Use ◽

Genotype By Environment ◽

N Supply ◽

Fertilizer Application Rate ◽

Use Efficiency ◽

N Status

Due to the asymptotic nature of the crop yield response curve to fertilizer N supply, the nitrogen use efficiency (NUE, yield per unit of fertilizer applied) of crops declines as the crop N nutrition becomes less limiting. Therefore, it is difficult to directly compare the NUE of crops according to genotype-by-environment-by-management interactions in the absence of any indication of crop N status. The determination of the nitrogen nutrition index (NNI) allows the estimation of crop N status independently of the N fertilizer application rate. Moreover, the theory of N dilution in crops indicates clearly that crop N uptake is coregulated by (i) soil N availability and (ii) plant growth rate capacity. Thus, according to genotype-by-environment-by-management interactions leading to variation in potential plant growth capacity, N demand for a given soil N supply condition would be different; consequently, the NUE of the crop would be dissimilar. We demonstrate that NUE depends on the crop potential growth rate and N status defined by the crop NNI. Thus, providing proper context to NUE changes needs to be achieved by considering comparisons with similar crop mass and NNI to avoid any misinterpretation. The latter needs to be considered not only when analyzing genotype-by-environment-by-management interactions for NUE but for other resource use efficiency inputs such as water use efficiency (colimitation N–water) under field conditions.

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Effects of nitrogen fertilizer on the grain yield and quality of winter oats

The Journal of Agricultural Science ◽

10.1017/s0021859698006042 ◽

1998 ◽

Vol 131 (4) ◽

pp. 395-407 ◽

Cited By ~ 14

Author(s):

A. G. CHALMERS ◽

C. J. DYER ◽

R. SYLVESTER-BRADLEY

Keyword(s):

N Fertilization ◽

N Fertilizer ◽

Limiting Factor ◽

N Recovery ◽

Soil N ◽

Fertilizer N ◽

Mean Values ◽

N Supply ◽

Site Variation ◽

N Fertility

Amounts of spring nitrogen (N) fertilizer (0–240 kg/ha), combined with three timing treatments (single, divided early or divided late), were tested at 14 sites in England and Wales between 1984 and 1988 to determine the optimum fertilizer N requirement for winter oats. The trials were superimposed on commercial crops of the cultivars Pennal (9 sites) or Peniarth (5 sites). Optimum amounts of N ranged from nil to 202 kg/ha (mean 119) and optimum yields varied between 5·8 and 9·9 t/ha (mean 7·3). Much (c. 60%) of the inter-site variation in N optimum was explained by differences in soil N supply, as indicated by N offtake in the grain at nil applied N. Mean yield differences between single and early (+0·08 t/ha) or late (−0·04 t/ha) divided dressings were slight, although significant (P<0·05) but inconsistent yield effects were obtained from early N at two sites and late N at three sites.Lodging occurred at 11 of the 12 sites where lodging scores were recorded and always increased significantly (P<0·05) with applied N. The amount of crop lodging at N optimum was, on an area basis, <50% at nine of the sites. The overall extent of site lodging was also influenced by soil N fertility and hence inversely related to N optimum. However, multiple regression, using site lodging as well as soil N supply, only accounted for slightly more (65%) of the variation in N optimum, which suggests that lodging was not a major limiting factor. Lodging was unexpectedly less from early N (mean 43%), but more from late N (53%) divided dressings, compared with a single N dressing (49%). Early N reduced lodging significantly (P<0·05) at four sites, although the actual reduction was only large at one site where early N also increased yield significantly (+0·57 t/ha).Grain N concentrations increased significantly (P<0·05) with applied N, on average by 0·12% per 40 kg/ha N increment. Timing effects on grain N concentration were very small, with mean values of 1·94, 1·91 and 1·96%N respectively from single, early and late divided dressings. Apparent recovery in grain of fertilizer N at the optimum amount ranged from 13 to 57% (mean 37), with better N recovery at the more yield-responsive sites. Changes in mean grain weight due to the amount and timing of fertilizer N were small, with an average reduction of 0·6 mg/grain per 40 kg/ha N applied. The adverse effects of N fertilizer on grain quality were slight and unlikely to have commercial significance. The agronomic implications of these results on the N fertilization of winter oats are discussed.

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

The Journal of Agricultural Science ◽

10.1017/s0021859621000988 ◽

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.

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Predicting the site specific soil N supply under winter wheat in Germany

Nutrient Cycling in Agroecosystems ◽

10.1007/s10705-017-9850-1 ◽

2017 ◽

Vol 110 (1) ◽

pp. 71-81 ◽

Cited By ~ 1

Author(s):

Arne M. Ratjen ◽

Henning Kage

Keyword(s):

Winter Wheat ◽

Soil N ◽

Site Specific ◽

N Supply

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Potentially mineralisable nitrogen: relationship to crop production and spatial mapping using infrared reflectance spectroscopy

Soil Research ◽

10.1071/sr08096 ◽

2009 ◽

Vol 47 (7) ◽

pp. 737 ◽

Cited By ~ 9

Author(s):

D. V. Murphy ◽

M. Osman ◽

C. A. Russell ◽

S. Darmawanto ◽

F. C. Hoyle

Keyword(s):

Grain Yield ◽

Crop Production ◽

Soil Analysis ◽

Sampling Strategy ◽

Ease Of Use ◽

Environmental Benefits ◽

Soil N ◽

Wheat Grain ◽

Inorganic N ◽

N Supply

Accurate and rapid prediction of the spatial structure of soil nitrogen (N) supply would have both economic and environmental benefits with respect to improved inorganic N fertiliser management. Yet traditional biochemical indices of soil N supply have not been widely incorporated into fertiliser decision support systems or environmental risk monitoring programs. Here we illustrate that in a low-input, semi-arid environment, potentially mineralisable N (PMN, as determined by anaerobic incubation) explained 21% of wheat grain yield (P = 0.003), whereas there was no significant relationship between wheat grain yield and inorganic N fertiliser application. We also assessed the spatial pattern of PMN using a structured grid soil sampling strategy over a 10-ha area (180 separate samples, 0–0.1 m). PMN in each soil sample was determined by standard biochemical analysis and also predicted using a fourier transform infrared spectrometer (FTIR). Findings illustrate that FTIR was able to significantly predict (P < 0.001) PMN values in soil and has the advantage of enabling high sample throughput and rapid (within minutes) soil analysis. Given the relatively low cost of FTIR machines and ease of use, such an approach has practical application in situations where analysis cost or access to equipped laboratories has hindered the measurement and monitoring of soil N supply within paddocks and across regions.

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