scholarly journals Rapid Soil Tests to Measure Mineralizable N Show Promise

CSA News ◽  
2018 ◽  
Vol 63 (12) ◽  
pp. 8-8
Keyword(s):  
Soil Tests ◽  
Mineralizable N

NITROGEN FERTILIZER REQUIREMENTS FOR BARLEY WHEN APPLIED WITH CATTLE MANURE CONTAINING WOOD SHAVINGS AS A SOIL AMENDMENT

1989 ◽  
Vol 69 (3) ◽  
pp. 515-523 ◽  
Author(s):  
D. C. MACKAY ◽  
J. M. CAREFOOT ◽  
T. G. SOMMERFELDT
Keyword(s):  
Protein Content ◽  
Residual Effect ◽  
N Fertilizer ◽  
Residual Effects ◽  
Yield Response ◽  
Soil Tests ◽  
Weather Factors ◽  
Hordeum Vulgare L ◽  
Chernozemic Soil ◽  
Mineralizable N

In an 8-yr experiment on an irrigated Dark Brown Chernozemic soil, four rates of N (0, 34, 67 and 101 kg ha−1), applied annually with 45 t ha−1 of manure containing softwood shavings (avg. of 46% dry wt) produced a linear yield response (from 3.5 with the check to 4.3 t ha−1 at the highest rate) of barley grain (Hordeum vulgare L. 'Galt'). There were large differences in yields among years, which could be attributed to weather factors, but there was no significant N × year response. Protein content increased linearly (from 11.2 to 13.5%), and both kernel weights and "test weights" (kg hL−1) decreased slightly but significantly with N applications. There was a pronounced "residual" effect of N rates on both grain yield (from 3.8 to 6.3 t ha−1) and protein content (from 10 to 13%) in the first year after applications of manure and N fertilizer ceased. These effects decreased rapidly and had practically disappeared by the end of the 3rd yr, although yields of all treatments remained high (about 5 t ha−1). Organic matter and N contents of the soil were increased by 70 and 41%, respectively, from the cumulative applications of shavings manure. It is concluded that application of manure containing large quantities of softwood shavings has a negligible effect on the N fertilizer requirements of the crop being grown. Beneficial residual effects of N fertilizer applied with the manure may result because of buildup of NO3-N throughout the soil profile, and likely also because of N release from readily mineralized organic compounds or microbial biomass. However, this effect was not reflected in soil tests for readily mineralizable N by NO3 incubation or KCl digestion methods and the effects were practically dissipated after 3 yr. The recovery of applied N fertilizer by the crops was high at all rates (61–79%), and essentially all of the N applied (fertilizer + manure) was accounted for by crop removal + increased soil N. Key words: Mineralizable-N soil tests, Chernozemic soil, repeated fertilizer applications, residual effects

Estimating and modelling the risk of redox-sensitive phosphorus loss from saturated soils using different soil tests

Geoderma ◽  
2021 ◽  
Vol 398 ◽  
pp. 115094
Author(s):  
G.J. Smith ◽  
R.W. McDowell ◽  
K. Daly ◽  
D. Ó hUallacháin ◽  
L.M. Condron ◽  
...  
Keyword(s):  
Saturated Soils ◽  
Soil Tests ◽  
Phosphorus Loss

EFFECT OF CROP ROTATION AND FERTILIZATION ON SOME BIOLOGICAL PROPERTIES OF A LOAM IN SOUTHWESTERN SASKATCHEWAN

1984 ◽  
Vol 64 (3) ◽  
pp. 355-367 ◽  
Author(s):  
V. O. BIEDERBECK ◽  
C. A. CAMPBELL ◽  
R. P. ZENTNER
Keyword(s):  
Microbial Biomass ◽  
Crop Residues ◽  
Biological Properties ◽  
Organic N ◽  
Microbial Biomass C ◽  
Rotation Length ◽  
Continuous Type ◽  
Mineralizable N ◽  
P Fertilizer ◽  
Potentially Mineralizable N

Effects of rotation length, fallow-substitute crops, and N and P fertilizer on some physical and biological properties of a Brown Chernozemic loam in southwestern Saskatchewan were determined over a period of 16 yr. After 12 yr, the erodible fraction in the top 15 cm of soil (i.e., < 0.84 mm) was inversely related to trash conserved and thus rotation length. Soil organic N (in the top 15 cm) increased from 0.18 to 0.20% in continuous-type rotations receiving an average 32 kg N∙ha−1∙yr−1 and adequate P, but it did not increase in continuous wheat receiving P only, nor in fallow rotations, except the one that included fall rye (Secale cereale L.). This N increase was credited partly to fertilizer and partly to more efficient use and cycling of subsoil NO3-N via plant roots and crop residues. After 10 yr, well-fertilized continuous-type rotations had a 13% greater C content than fallow rotations and continuous wheat receiving only P. In the top 7.5 cm of soil under the four rotations examined in detail, bacterial numbers were lowest in fallow-wheat, intermediate in fallow-wheat-wheat, higher in continuous wheat receiving N and P, and highest in continuous wheat receiving only P. Similarly, microbial biomass C in these four rotations was 180, 226, 217 and 357 kg∙ha−1; biomass N was 52, 65, 54 and 72 kg∙ha−1; and biomass C/N ratios were 3.4, 3.5, 4.1 and 5.1, respectively. Differences in biomass C/N, respiration rates and numbers of bacteria, actinomycetes and yeasts indicated both quantitative and qualitative microbial changes and reflected increasing rotation length and differences in fertility. Potentially mineralizable N (No) was 192 kg∙ha−1 for adequately fertilized continuous wheat, and exceeded No in fallow-wheat by 45%, in fallow-wheat-wheat by 17% and in continuous wheat receiving only P by 25%. The latter rotation contained a large but fairly inactive microbial population. We concluded that land degradation caused by frequent summerfallowing can be arrested and the decline in amount and quality of organic matter reversed by use of available agronomic technology. Key words: Microbial biomass, microbial activity, potentially mineralizable N, respiration, soil erodibility

Analytical stress-strain relation for soils

2021 ◽  
Author(s):  
Kristian Krabbenhoft ◽  
J. Wang
Keyword(s):  
Test Data ◽  
Narrow Range ◽  
Strain Range ◽  
Data Sets ◽  
Soil Tests ◽  
Stress Strain ◽  
Strain Relation ◽  
Stress Strain Relation ◽  
Typical Test ◽  
Typical Soil

A new stress-strain relation capable of reproducing the entire stress-strain range of typical soil tests is presented. The new relation involves a total of five parameters, four of which can be inferred directly from typical test data. The fifth parameter is a fitting parameter with a relatively narrow range. The capabilities of the new relation is demonstrated by the application to various clay and sand data sets.

Applying Model for Water Pollution commencing Non-Point Resource Based on Statistical Data in River

2020 ◽  
Vol 51 (1) ◽  
pp. 03-04
Author(s):  
Leon Kirk
Keyword(s):  
Statistical Data ◽  
Nonpoint Source ◽  
Direct Result ◽  
Soil Tests ◽  
Soil P ◽  
Water Condition ◽  
Farmland Soil ◽  
Source Contamination ◽  
Landscape Geography ◽  
Spatial Area

Eutrophication is an overall contamination issue, when the directresource contamination is proficiently unnatural; contamination load from non-point foundation has the expanding extent in the complete burden. The investigation on non-point foundation contamination is a significant perspective in the exploration on water condition contamination. The nonpoint source contamination, highlighted by broad inclusion, dynamic intricacy and troublesome evaluation of precise spatial area and release degree, is a solution and troublesome concern for the investigation of water condition contamination. In this magazine, an improved fare co-efficient strategy is projected to gauge non-point foundation contamination load in watersheds, same thinking about the impacts of precipitation and the decrease of toxin during the time spent vehicle. The measures of downpour and overflow are enormous in soaked years, so the non-point foundation contamination heaps created are huge too in different years, the non-point foundation contamination loads are fewer a direct result of less precipitation in typical water years. Non-point resource contamination factors are investigated, for example, precipitation, land use, landscape, geography and soil P speciation in farmland soil tests in forest soil tests, and in orchardland soil tests.

scholarly journals Incubation methods for assessing mineralizable nitrogen in soils under sugarcane

2013 ◽  
Vol 37 (2) ◽  
pp. 450-461 ◽  
Author(s):  
Eduardo Mariano ◽  
Paulo Cesar Ocheuze Trivelin ◽  
José Marcos Leite ◽  
Michele Xavier Vieira Megda ◽  
Rafael Otto ◽  
...  
Keyword(s):  
N Mineralization ◽  
Standard Technique ◽  
Extraction Methods ◽  
N Fertilization ◽  
Chemical Extraction ◽  
Net N Mineralization ◽  
Anaerobic Incubation ◽  
Aerobic Incubation ◽  
Mineralizable N

Considering nitrogen mineralization (N) of soil organic matter is a key aspect for the efficient management of N fertilizers in agricultural systems. Long-term aerobic incubation is the standard technique for calibrating the chemical extraction methods used to estimate the potentially mineralizable N in soil. However, the technique is laborious, expensive and time-consuming. In this context, the aims of this study were to determine the amount of soil mineralizable N in the 0-60 cm layer and to evaluate the use of short-term anaerobic incubation instead of long-term aerobic incubation for the estimation of net N mineralization rates in soils under sugarcane. Five soils from areas without previous N fertilization were used in the layers 0-20, 20-40 and 40-60 cm. Soil samples were aerobically incubated at 35 ºC for 32 weeks or anaerobically incubated (waterlogged) at 40 ºC for seven days to determine the net soil N mineralization. The sand, silt and clay contents were highly correlated with the indexes used for predicting mineralizable N. The 0-40 cm layer was the best sampling depth for the estimation of soil mineralizable N, while in the 40-60 cm layer net N mineralization was low in both incubation procedures. Anaerobic incubation provided reliable estimates of mineralizable N in the soil that correlated well with the indexes obtained using aerobic incubation. The inclusion of the pre-existing NH4+-N content improved the reliability of the estimate of mineralizable N obtained using anaerobic incubation.

scholarly journals Prediction of zinc deficiency in navy beans (Phaseolus vulgaris) by soil and plant analyses

1990 ◽  
Vol 30 (4) ◽  
pp. 557 ◽  
Author(s):  
JD Armour ◽  
AD Robson ◽  
GSP Ritchie
Keyword(s):  
Phaseolus Vulgaris ◽  
Soil Solution ◽  
Relative Yield ◽  
Fresh Weight ◽  
Soil Tests ◽  
Plant Parts ◽  
Zn Concentration ◽  
Navy Beans ◽  
Glasshouse Experiment ◽  
Zn Status

Navy beans (Phaseolus vulgaris cv. Gallaroy) were grown with 7 rates of zinc (Zn) in a Zn-deficient gravelly sandy loam in a glasshouse experiment. The plant shoots were harvested 31 days after sowing and the Zn concentration in each of 4 plant parts (YL, young leaf; YOL, young open leaf; YFEL, youngest fully expanded leaf; and whole shoots) was related to the fresh weight of the shoots. The critical Zn concentrations (mgtkg) in the plant parts determined by the 2 intersecting straight lines model were 21.1 for YL (r2 = 0.66), 17.1 for YOL (r2 = 0.83), 10.6 for YFEL (r2 = 0.91) and 12.5 for the whole tops (r2 = 0.88). The YFEL was selected as an appropriate diagnostic tissue because it is readily identifiable in the field and had the highest 1.2 with fresh weight. In a second glasshouse experiment, the critical Zn concentration in the YFEL and 5 soil tests were evaluated for their ability to predict the Zn status of navy beans. There were 13 soils from sands to clays with a wide range of chemical properties. The soil tests were 0.1 mol/L HCl, DTPA, EDTA, dilute CaCl2 and soil solution Zn. The concentration of Zn in the YFEL correctly predicted Zn deficiency or adequacy in about 77% of samples. The results from both experiments showed that a critical Zn concentration of 10-11 mg/kg in the YFEL can be used to diagnose the Zn status of Gallaroy navy beans. It was not possible to recommend a single soil test for prediction of the relative yield of navy beans. A combination of quantity (HCl, EDTA, DTPA) and intensity (soil solution, 0.002 mol/L CaCl2, 0.01 mol/L CaCl2) parameters were able to explain most of the variation in the Zn concentration of the YFEL, a more sensitive measure of nutrient availability than relative yield. EDTA-Zn in combination with 0.01 mol/L CaCl2-Zn explained 90% of the variation in the Zn concentration in the YFEL, while HCl- or DTPA-Zn and 0.01 mol/L CaCl2 explained about 80% of the variation. As soil solution Zn was significantly correlated with 0.002 and 0.01 mol/L CaCl2-Zn (r = 0.75, P<0.01; r = 0.62, P<0.05, respectively), CaCl2-Zn may be used as a more convenient measure of Zn intensity than soil solution Zn.

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