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

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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Effect of nitrogen fertilizer applied to winter oilseed rape (Brassica napus) on soil mineral nitrogen after harvest and on the response of a succeeding crop of winter wheat to nitrogen fertilizer

The Journal of Agricultural Science ◽

10.1017/s002185960008881x ◽

1996 ◽

Vol 126 (1) ◽

pp. 63-74 ◽

Cited By ~ 36

Author(s):

M. A. Shepherd ◽

R. Sylvester-Bradley

Keyword(s):

Organic Matter ◽

Oilseed Rape ◽

Nitrogen Fertilizer ◽

Organic Matter Content ◽

Matter Content ◽

Mineral Nitrogen ◽

Fertilizer N ◽

Soil Mineral ◽

Soil Mineral Nitrogen ◽

Optimum Amount

SUMMARYSoil mineral nitrogen (Nmin) was measured to 90 cm at a total of 12 sites in the UK in the autumn after an oilseed rape experiment, which measured responses to fertilizer N. On average, Nmin, increased by 15 kg/ha per 100 kg/ha fertilizer nitrogen (N) applied to the rape, up to the economic optimum amount of N (Nmin). There were larger increases in Nmin where fertilizer applications exceeded Nopt, thus super-optimal fertilizer applications disproportionately increased the amount of nitrate likely to leach over-winter. The small effects of sub-optimal N on Nmin were associated with large increases in N offtake by the oilseed rape, whereas the larger effects of super-optimal N on Nmin were associated with only small increases in N offtake. Over 70% of the variation in autumn Nmin was explained by the previous rape's N fertilizer rate and the topsoil organic matter content.Nitrogen applied to the rape increased grain yields of the succeeding wheat crops when no further fertilizer N was applied to the wheat. It was concluded that N applied to oilseed rape significantly affected Nmin after harvest, and these effects were not completely nullified by leaching over-winter, so soil N supply to the succeeding wheat crop was significantly increased. Responses in grain yield indicated that each 100 kg/ha N applied to the rape provided N equivalent to c. 30 kg/ha for the following cereal. Each 1% of soil organic matter further contributed N to the wheat, equivalent to 25 kg/ha.It is important to ensure that oilseed rape receives no more than the optimum amount of fertilizer N if subsequent leaching is to be minimized. Reductions below optimum amounts will have only a small effect on leaching. Substantial changes in the economic optimum N for rape production should be accompanied by adjustment in fertilizer N application to following wheat crops. Fertilizer recommendation systems for wheat should take account of the fertilizer N applied to the preceding oilseed rape and the topsoil organic matter content.

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Relation between soil mineral nitrogen before sowing and optimum nitrogen fertilization in onions

Netherlands Journal of Agricultural Science ◽

10.18174/njas.v43i3.571 ◽

1995 ◽

Vol 43 (3) ◽

pp. 333-345

Author(s):

C.L.M. De Visser ◽

W. Van Den Berg ◽

H. Niers

Keyword(s):

Response Function ◽

Nitrogen Fertilizer ◽

Strong Relationship ◽

Application Rate ◽

Mineral Nitrogen ◽

Soil Mineral ◽

Soil Mineral Nitrogen ◽

Fixed Rate ◽

Fertilizer Nitrogen ◽

The Relationship

To study the relationship between the amount of soil mineral nitrogen before sowing of onions (Nmin) and the optimum amount of nitrogen fertilizer (Nopt), 36 multilevel fertilizer nitrogen trials were conducted in the Netherlands between 1978 and 1982. For 26 trials Nopt was within the studied range (0-200 kg N/ha) and could be estimated using a quadratic response function. A significant linear relationship between Nopt and Nmin before sowing was only found when Nmin in the layer 0-30 cm was considered. The same 26 trials were analysed together using a quadratic and a linear exponential response function. However, with both methods the yield predicted from Nmin did not prove to be superior to a fixed nitrogen application rate of about 125 kg of nitrogen/ha. A verification pointed out that the relationship overestimated the opt. amount of fertilizer nitrogen found in 8 independent multilevel fertilizer nitrogen trials. A fixed rate of 100-125 kg of nitrogen/ha yielded better results. The possible reasons for the absence of a strong relationship between the amount of soil mineral nitrogen before sowing and the opt. amount of nitrogen fertilizer are discussed.

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Field experiments with slurry and dicyandiamide: response of potatoes and effects on soil mineral nitrogen

Netherlands Journal of Agricultural Science ◽

10.18174/njas.v41i2.625 ◽

1993 ◽

Vol 41 (2) ◽

pp. 95-109

Author(s):

W.P. Wadman ◽

J.J. Neeteson ◽

G.J. Wijnen

Keyword(s):

Nitrogen Fertilizer ◽

Field Experiments ◽

Inorganic Nitrogen ◽

Maximum Yield ◽

Soil Layer ◽

Nitrification Inhibitor ◽

Mineral Nitrogen ◽

Residual Soil ◽

Soil Mineral ◽

Soil Mineral Nitrogen

In the period of 1983-1985, 18 field experiments with potatoes grown for industrial starch production were set up in the Netherlands to investigate the effects of poultry-slurry application on tuber yield and on soil mineral nitrogen. Slurry was applied in autumn with and without the nitrification inhibitor dicyandiamide (DCD) and in spring without DCD. Control treatments without slurry or DCD were included. Various nitrogen fertilizer rates were applied to all slurry treatments. In autumn, following slurry application without DCD, slurry-derived nitrate moved to the 0.3-0.6 and 0.6-1 m soil layers. Following DCD-application, most of the slurry-derived nitrate remained in the 0-0.3 m soil layer. Maximum yields as estimated from a nitrogen fertilizer response function were slightly increased by the slurry application. Nitrogen supplied from the slurry decreased the amount of fertilizer nitrogen needed for maximum yield. Increasing the amounts of soil mineral nitrogen in June from slurry or applied inorganic nitrogen fertilizer increased residual soil mineral nitrogen at harvest.

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

European Journal of Agronomy ◽

10.1016/j.eja.2009.05.006 ◽

2009 ◽

Vol 31 (2) ◽

pp. 103-109 ◽

Cited By ~ 64

Author(s):

Branko Kramberger ◽

Anastazija Gselman ◽

Marjan Janzekovic ◽

Mitja Kaligaric ◽

Brigita Bracko

Keyword(s):

Nitrogen Content ◽

Cover Crops ◽

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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