Mulching Effects on Labile Soil Organic Nitrogen Pools under a Spring Maize Cropping System in Semiarid Farmland

2015 ◽  
Vol 107 (4) ◽  
pp. 1465-1472 ◽  
Author(s):  
Shasha Luo ◽  
Lin Zhu ◽  
Jianliang Liu ◽  
Lingduo Bu ◽  
Shanchao Yue ◽  
...  
Keyword(s):  
Organic Nitrogen ◽  
Cropping System ◽  
Soil Organic Nitrogen ◽  
Nitrogen Pools ◽  
Spring Maize

Derterminatin of the mineralization coefficient of soil organic nitrogen on two soils at Katherine, NT

1967 ◽  
Vol 7 (26) ◽  
pp. 266 ◽  
Author(s):  
R Wetselaar
Keyword(s):  
Organic Nitrogen ◽  
Nitrate Nitrogen ◽  
Cropping System ◽  
First Year ◽  
Soil Organic Nitrogen ◽  
Legume Crop ◽  
Decomposition Constant ◽  
Nitrogen Yields ◽  
The Mean

The mineralization coefficient (M.C.) (the amount of nitrate nitrogen formed in one season in sift, by bare fallowing the soil, as a percentage of the amount of organic nitrogen in the topsoil at the onset of the season) was measured on two soils at Katherine, N.T. The determination of M.C. is regarded as useful in evaluating the 'true' decomposition constant of a soil under annual cropping conditions. Its relation to the 'apparent' decomposition constant is discussed. Tippera clay loam had a mean M.C. of 4.80 per cent, and the fluctuations around the mean were positively related to amount of rainfall. The M.C. for Blain sand dropped from 12.5 per cent in the first year of cultivation to 5.0 per cent in the third and fourth years. The data indicate that the initial high nitrogen yields on the sandy soil will in time decline to a low level unless a legume crop is incorporated in the cropping system.

scholarly journals Different forms of nitrogen deposition show variable effects on soil organic nitrogen turnover in a temperate forest

2022 ◽  
Vol 169 ◽  
pp. 104212
Author(s):  
Jihui Tian ◽  
Kai Wei ◽  
Tao Sun ◽  
Nan Jiang ◽  
Zhenhua Chen ◽  
...  
Keyword(s):  
Nitrogen Deposition ◽  
Temperate Forest ◽  
Organic Nitrogen ◽  
Soil Organic Nitrogen ◽  
Nitrogen Turnover

Tillage effects on labile pools of soil organic nitrogen in a semi-humid climate of Argentina: A long-term field study

2017 ◽  
Vol 169 ◽  
pp. 71-80 ◽  
Author(s):  
Juan M. Martínez ◽  
Juan A. Galantini ◽  
Matias E. Duval ◽  
Fernando M. López
Keyword(s):  
Field Study ◽  
Organic Nitrogen ◽  
Humid Climate ◽  
Soil Organic Nitrogen ◽  
Term Field

Increased growth and uptake of nutrients by corn plants treated with low levels of simazine

1965 ◽  
Vol 16 (3) ◽  
pp. 257 ◽  
Author(s):  
JR Freney
Keyword(s):  
Dry Matter ◽  
Organic Nitrogen ◽  
Control Plant ◽  
Solution Culture ◽  
Available Nitrogen ◽  
Protein Nitrogen ◽  
Soil Organic Nitrogen ◽  
Low Levels ◽  
Corn Plants ◽  
Uptake Of Nutrients

Simazine applications of 1.5 p.p.m. to soil in pots in a glasshouse increased dry matter yields and uptake of nitrogen in corn only when additional nitrogen was applied to the soil. The proportions of protein and non-protein nitrogen in the topgrowth were not affected. Application of simazine at this rate without addition of nitrogen resulted in increased leaf area but did not significantly affect yield. Simazine provided a stimulus to the plant early in its life and enabled it to grow faster than the control plant. When the supply of available nitrogen was exhausted the simazine effect decreased. When incubated with soil, simazine did not increase mineralization of soil organic nitrogen, nor did it have any effect on immobilization of mineral nitrogen. Simazine applied at 0.06 p.p.m. in solution culture increased the yield of corn tops by 36%, the uptake of nitrogen by 37%, phosphorus by 25%, magnesium by 24%, and potassium by 41 %. It had no effect on the yields of roots. The results suggest that simazine increased plant growth by a direct effect on plant metabolism and not through any interaction with the soil.

scholarly journals Do plants use root-derived proteases to promote the uptake of soil organic nitrogen?

2020 ◽  
Vol 456 (1-2) ◽  
pp. 355-367
Author(s):  
Lucy M. Greenfield ◽  
Paul W. Hill ◽  
Eric Paterson ◽  
Elizabeth M. Baggs ◽  
Davey L. Jones
Keyword(s):  
Protease Activity ◽  
Organic Nitrogen ◽  
N Uptake ◽  
Root Surface ◽  
Organic N ◽  
Soil Organic Nitrogen ◽  
Poor Access ◽  
N Deficiency ◽  
Almost All ◽  
Soil Protein

Abstract Aims The capacity of plant roots to directly acquire organic nitrogen (N) in the form of oligopeptides and amino acids from soil is well established. However, plants have poor access to protein, the central reservoir of soil organic N. Our question is: do plants actively secrete proteases to enhance the breakdown of soil protein or are they functionally reliant on soil microorganisms to undertake this role? Methods Growing maize and wheat under sterile hydroponic conditions with and without inorganic N, we measured protease activity on the root surface (root-bound proteases) or exogenously in the solution (free proteases). We compared root protease activities to the rhizosphere microbial community to estimate the ecological significance of root-derived proteases. Results We found little evidence for the secretion of free proteases, with almost all protease activity associated with the root surface. Root protease activity was not stimulated under N deficiency. Our findings suggest that cereal roots contribute one-fifth of rhizosphere protease activity. Conclusions Our results indicate that plant N uptake is only functionally significant when soil protein is in direct contact with root surfaces. The lack of protease upregulation under N deficiency suggests that root protease activity is unrelated to enhanced soil N capture.

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