A SOIL CORE METHOD FOR ESTIMATING N-MINERALIZATION AND DENITRIFICATION DURING COVER CROP DECOMPOSITION

The USDA Forest Service initiated a national study in the early 1990s to examine the effects of organic matter removal, compaction, and vegetation control on tree growth and soil processes at several locations across the United States and Canada. Our study was undertaken on the Lower Coastal Plain of North Carolina installation during the second and the fifth growing seasons following loblolly pine (Pinus taeda L.) plantation establishment. We used the in situ soil core incubation method to assess net N mineralization, and collections were conducted monthly from March to December in 1993 and 1996. The largest differences in N mineralization resulted from soil type differences between blocks. Organic matter removal did not affect N mineralization in either year; however, compaction reduced N mineralization during both years. Vegetation control had a pronounced positive effect on N mineralization and was only slightly less important as compared with soil type. Mineralization rates in year 5 were 80% less than in year 2. We hypothesized that the high N mineralization rates in year 2 may be related to a decrease in the input of soluble organic C following harvest (reducing immobilization), a quick mineralization of microbial N, fluctuating soil temperature and water conditions, and fine roots and litter biomass input following harvest.

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Soil carbon and nitrogen mineralization under different tillage systems and Permanent Groundcover cultivation between Orange trees

Revista Brasileira de Fruticultura ◽

10.1590/s0100-29452011005000071 ◽

2011 ◽

Vol 33 (2) ◽

pp. 637-648 ◽

Cited By ~ 5

Author(s):

Elcio Liborio Balota ◽

Pedro Antonio Martins Auler

Keyword(s):

Cover Crop ◽

N Mineralization ◽

Conventional Tillage ◽

Tree Canopy ◽

Soil Tillage ◽

Tillage Systems ◽

C And N Mineralization ◽

C And N ◽

Strip Tillage ◽

Row Space

The objective of this work was to evaluate the alterations in carbon and nitrogen mineralization due to different soil tillage systems and groundcover species for intercropped orange trees. The experiment was established in an Ultisol soil (Typic Paleudults) originated from Caiuá sandstone in northwestern of the state of Paraná, Brazil, in an area previously cultivated with pasture (Brachiaria humidicola). Two soil tillage systems were evaluated: conventional tillage (CT) in the entire area and strip tillage (ST) with a 2-m width, each with different groundcover vegetation management systems. The citrus cultivar utilized was the 'Pera' orange (Citrus sinensis) grafted onto a 'Rangpur' lime rootstock. The soil samples were collected at a 0-15-cm depth after five years of experiment development. Samples were collected from under the tree canopy and from the inter-row space after the following treatments: (1) CT and annual cover crop with the leguminous Calopogonium mucunoides; (2) CT and perennial cover crop with the leguminous peanut Arachis pintoi; (3) CT and evergreen cover crop with Bahiagrass Paspalum notatum; (4) CT and cover crop with spontaneous B. humidicola grass vegetation; and (5) ST and maintenance of the remaining grass (pasture) of B. humidicola. The soil tillage systems and different groundcover vegetation influenced the C and N mineralization, both under the tree canopy and in the inter-row space. The cultivation of B. humidicola under strip tillage provided higher potential mineralization than the other treatments in the inter-row space. Strip tillage increased the C and N mineralization compared to conventional tillage. The grass cultivation increased the C and N mineralization when compared to the others treatments cultivated in the inter-row space.

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The effect of a perennial cover crop on net soil N mineralization and microbial biomass carbon in coconut plantations in the humid tropics

Soil Use and Management ◽

10.1111/j.1475-2743.2010.00272.x ◽

2010 ◽

Vol 26 (2) ◽

pp. 158-166 ◽

Cited By ~ 6

Author(s):

C. B. Pandey ◽

M. Begum

Keyword(s):

Microbial Biomass ◽

Cover Crop ◽

N Mineralization ◽

Microbial Biomass Carbon ◽

Humid Tropics ◽

Biomass Carbon ◽

Soil N ◽

Soil N Mineralization

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Application of a soil core method to investigate the effect of oxygen concentration on denitrification

Soil Biology and Biochemistry ◽

10.1016/0038-0717(84)90027-0 ◽

1984 ◽

Vol 16 (4) ◽

pp. 331-334 ◽

Cited By ~ 55

Author(s):

Timothy B. Parkin ◽

James M. Tiedje

Keyword(s):

Oxygen Concentration ◽

Soil Core ◽

Core Method ◽

Effect Of Oxygen

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First Record of the Genus Myopias (Hymenoptera, Formicidae) from India, with Description of New Species

Vestnik Zoologii ◽

10.2478/v10058-012-0006-0 ◽

2012 ◽

Vol 46 (1) ◽

pp. e-33-e-35 ◽

Cited By ~ 1

Author(s):

H. Bharti ◽

A. Wachkoo

Keyword(s):

New Species ◽

Body Size ◽

First Record ◽

Soil Core ◽

Northwest Himalaya ◽

Reduced Body ◽

Core Method ◽

First Time ◽

Single Worker

First Record of the Genus Myopias (Hymenoptera, Formicidae) from India, with Description of New Species Myopias shivalikensis Bharti et Wachkoo, sp. n. is described based on a single worker, collected in lower Shivalik range (700 m a. s. l.) of Northwest Himalaya by soil core method. The genus Myopias is recorded for the first time in India. M. shivalikensis is a cryptobiotic species with reduced body size and rudimentary eyes. It is similar to M. nops Willey et Brown, 1983, distinctly differing from all described species of this genus.

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Factors affecting nitrate leaching from a calcareous loam in East Anglia

The Journal of Agricultural Science ◽

10.1017/s0021859600088821 ◽

1996 ◽

Vol 126 (1) ◽

pp. 75-86 ◽

Cited By ~ 49

Author(s):

D. B. Davies ◽

T. W. D. Garwood ◽

A. D. H. Rochford

Keyword(s):

Nitrate Leaching ◽

Cover Crops ◽

Cover Crop ◽

N Mineralization ◽

N Leaching ◽

Aquifer Recharge ◽

Soil Mineral Nitrogen ◽

East Anglia ◽

Factors Affecting ◽

Cover Cropping

SUMMARYThe effects of overwinter cover cropping, delayed ploughing and method of straw disposal on the quantities of nitrate leached (averaged over three winters during 1989–93) from a chalk loam in Eastern England were examined. The recovery of ‘retained’ nitrogen (retained through cover crop uptake, delayed ploughing and immobilization by straw) in a following spring crop was also assessed. In the first two winters, the rye cover crop decreased nitrate leaching by > 90% (28 kg N/ha per year), as compared with bare fallow treatments. In 1992/93 this decrease was only 23% (10 kg/ha), due to the early onset of drainage before cover was well established. Delayed ploughing on bare treatments, to decrease autumn N mineralization and subsequent nitrate leaching, was ineffectual in 1989/90 but had substantial effects in 1990/91 and 1992/93; N mineralization, inferred from soil mineral nitrogen content, and nitrate leaching were decreased by 31 and 35% in 1990/91 and by 36 and 61% in 1992/93, respectively. Nitrate leaching (averaged over three winters) was unaffected by straw incorporation. There was no evidence of recovery of cover crop N in the spring sown test crops (barley or sugarbeet). In the low soil N input situation encountered in this experiment, it was unnecessary to sow cover crops before early September in years of average or below average rainfall to ensure that the average soil solution concentrations remained below the EU drinking water limit of 11 mg NO3-N/1. However, in wetter seasons substantial N leaching occurred before cover had taken up much N. In 1992/93 N retained against leaching by a rye cover crop in previous years was apparently being remobilized and lost through leaching, although if cover was grown again there was less leaching than from bare land. In the future, an increase in the extent of cover cropping might increase transpiration rates and therefore lead to a decrease in aquifer recharge.

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