Effects of cover crops on soil mineral nitrogen and on the yield and nitrogen content of maize

Wheat was grown in a series of 1:1 rotation cycles with sweet lupins over 8 years on three sites in Western Australia. Grain yield of wheat was the main test used to compare five lupin management treatments with a control treatment, 'no-lupins'. The lupins were cut as for silage, cut as for hay, or harvested as mature grain, the stubble being burnt or removed in summer, or turned into the soil the next autumn. Nitrogen taken up in the lupins and in the wheat was measured, as well as soil mineral nitrogen in the top 10 cm in the final year. Lupin yield and nitrogen content within any year were similar over all treatments. As much nitrogen was removed in hay and silage as in mature lupins, but wheat yielded most grain after the 'silage' and 'hay' treatments, and least after 'no-lupins' or after the 'remove' and 'turn-in' stubble treatments. Nitrogen uptakes in young wheat plants point to treatment effects due to differences in nitrogen availability, but the treatments also caused different weed populations which at least partially affected wheat yields. Herbicide control of encroaching weeds in the lupins raised soil nitrate levels the following summer and increased subsequent wheat yields.

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The role of cover crops in irrigated systems: Water balance, nitrate leaching and soil mineral nitrogen accumulation

Agriculture Ecosystems & Environment ◽

10.1016/j.agee.2012.03.021 ◽

2012 ◽

Vol 155 ◽

pp. 50-61 ◽

Cited By ~ 70

Author(s):

J.L. Gabriel ◽

R. Muñoz-Carpena ◽

M. Quemada

Keyword(s):

Water Balance ◽

Nitrate Leaching ◽

Cover Crops ◽

Mineral Nitrogen ◽

Nitrogen Accumulation ◽

Soil Mineral ◽

Soil Mineral Nitrogen

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NITROGEN FERTILIZER REQUIREMENTS OF FRUIT TREES AS RELATED TO SOIL MINERAL NITROGEN CONTENT IN SPRING

Acta Horticulturae ◽

10.17660/actahortic.1980.92.58 ◽

1980 ◽

pp. 353-354

Author(s):

J. WEHRMANN ◽

H.C. SCHARPF

Keyword(s):

Nitrogen Content ◽

Nitrogen Fertilizer ◽

Fruit Trees ◽

Mineral Nitrogen ◽

Soil Mineral ◽

Soil Mineral Nitrogen

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The influence of water on wheat yield, plant nitrogen uptake and soil mineral nitrogen concentration

Australian Journal of Experimental Agriculture ◽

10.1071/ea9650310 ◽

1965 ◽

Vol 5 (18) ◽

pp. 310 ◽

Cited By ~ 7

Author(s):

RR Storrier

Keyword(s):

Grain Yield ◽

Nitrogen Content ◽

Dry Matter ◽

Mineral Nitrogen ◽

Wheat Crop ◽

Soil Mineral ◽

Soil Mineral Nitrogen ◽

Grain Number ◽

Plant Nitrogen ◽

Stage Of Development

Water, in addition to the natural rainfall, was applied at five different stages of crop development to Heron wheat growing on a highly fertile soil. Dry matter yield, grain yield, the grain yield parameters (ear number, grain number per ear, weight per grain), and nitrogen content were measured. Changes in soil mineral nitrogen content as a consequence of water application and subsequent plant uptake were also studied. A single application of water at jointing, and treatments involving watering at all pre-anthesis stages during a period of moisture stress, increased straw and grain yields and floret development, as reflected in grain number per ear. Water applied after anthesis controlled to some degree the loss of dry matter and plant nitrogen exhibited by a maturing wheat crop. The number of tillers produced, the number surviving, or the number of ears were not increased by adding water at any stage of development. The increased grain yield that followed late additions of water was due to increases in the weight per grain. The addition of water during the jointing to milk stage increased the uptake of mineral nitrogen by the crop, to a depth of 30 inches. No increase in the mineralization of organic nitrogen was detected by soil analysis, but an approximate balance sheet indicated that mineralization, which was occurring during the growing season, was further stimulated by watering.

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