Effect of distance and depth on microbial biomass and mineral nitrogen content under Acacia senegal (L.) Willd. trees

When organic materials of high nitrogen content were allowed to decompose in soil, the accumulation of ammonium caused high pH. It vas shown that high pH caused increased production of carbon dioxide, sulphate, and mineral nitrogen from soil organic matter.

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Effect of lupin management on the yield of subsequent wheat crops in a lupin-wheat rotation

Australian Journal of Experimental Agriculture ◽

10.1071/ea9850603 ◽

1985 ◽

Vol 25 (3) ◽

pp. 603 ◽

Cited By ~ 2

Author(s):

A Petch ◽

RW Smith

Keyword(s):

Grain Yield ◽

Nitrogen Content ◽

Western Australia ◽

Treatment Effects ◽

Nitrogen Availability ◽

Mineral Nitrogen ◽

Control Treatment ◽

Soil Nitrate ◽

Soil Mineral ◽

Soil Mineral Nitrogen

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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Cattle Horn Shavings: A Possible Nitrogen Source for Apple Trees

Agronomy ◽

10.3390/agronomy11030540 ◽

2021 ◽

Vol 11 (3) ◽

pp. 540

Author(s):

Juozas Lanauskas ◽

Nobertas Uselis ◽

Loreta Buskienė ◽

Romas Mažeika ◽

Gediminas Staugaitis ◽

...

Keyword(s):

Ammonium Nitrate ◽

Nitrogen Content ◽

Nitrogen Nutrition ◽

Agricultural Waste ◽

Leaf Nitrogen ◽

Mineral Nitrogen ◽

Research Centre ◽

Leaf Nitrogen Content ◽

Apple Trees ◽

Orchard Soil

The circular economy concept promotes the recycling of agricultural waste. This study was aimed at investigating the effects of cattle horn shavings on apple tree nitrogen nutrition. Ligol apple trees on P 60 rootstock were the object of the study. The experiment was conducted in the experimental orchard of the Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry, from 2015 to 2018. Two fertiliser rates were tested: 50 and 100 kg/ha N. Horn shavings (14.1% N) were applied at the end of autumn or at the beginning of vegetation in the spring and in one treatment 100 kg/ha N rate was divided into two equal parts and applied both in autumn and spring. The effects of the horn shavings were compared with the effects of ammonium nitrate (34.4% N) and the unfertilised treatment. The lowest mineral nitrogen content was found in the unfertilised orchard soil and the soil fertilised with horn shavings in the spring at 50 kg/ha N equivalent. In all other cases, the fertilisers increased the soil’s mineral nitrogen content. The lowest leaf nitrogen content was found in apple trees that grew in the unfertilised orchard soil or soil fertilised in the spring with 50 kg/ha N of horn shavings (1.58–2.13%). In other cases, leaf nitrogen content was higher (1.77–2.17%). The apple trees with the lowest leaf nitrogen content produced the smallest average yield (34.5–36.6 t/ha). The highest yield was recorded from fruit trees fertilised with 50 kg/ha N of ammonium nitrate applied in spring or horn shavings applied in autumn (42.4 and 41.4 t/ha, respectively). The influence of horn shavings on the other studied parameters was similar to that of ammonium nitrate. Horn shavings, like nitrogen fertiliser, could facilitate nitrogen nutrition management in apple trees, especially in organic orchards, where the use of synthetic fertilisers is prohibited.

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Corrigenda - Temporal fluctuations in biochemical properties of soil under pasture. I. Respiratory activity and microbial biomass

Soil Research ◽

10.1071/sr9840303c ◽

1984 ◽

Vol 22 (3) ◽

pp. 303

Author(s):

DJ Ross ◽

VA Orchard ◽

DA Rhoades

Keyword(s):

Soil Moisture ◽

Microbial Biomass ◽

Moisture Content ◽

Respiratory Activity ◽

Mineral Nitrogen ◽

Co2 Production ◽

Biomass Carbon ◽

Moist Soil ◽

Glucose Response ◽

Temporal Fluctuations

Temporal fluctuations in respiratory activity (CO2 production) and two indices of microbial biomass (biomass carbon and mineral-nitrogen flush contents) were determined in topsoil, predominantly a Typic Haplaquoll, from a site under grazed pastures in the Wairarapa area. Samples, with organic carbon contents averaging 6.7 and 3.6%, were taken from two separate plots at c. 4-weekly intervals for over a year. Biomass indices were estimated by the chloroform fumigation technique. The suitability of a physiological procedure for indicating biomass fluctuations was also investigated. Correlations between properties were calculated with plot effects removed. Rates of CO2 production by field-moist soil, and soil at a standardized water potential, were lowest in samples taken at the driest time of the year and correlated significantly with field-moisture content. In contrast, biomass carbon estimates were generally highest in late summer and autumn, and lowest in winter, and were correlated negatively with soil moisture content. Mineral-nitrogen flush fluctuations were less marked, and not significantly related to soil moisture or biomass carbon content. In the physiological procedure, using field-moist soil, neither rates of CO2 production by soil + glucose, nor net glucose response values, were correlated significantly with biomass carbon estimated by the fumigation technique. This procedure therefore appears unsuitable for estimating temporal fluctuations in the biomass of an individual soil under pasture.

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Observations on the effect of organic materila upon aggregation and nitrate-nitrogen content of soil

Agricultural and Food Science ◽

10.23986/afsci.71323 ◽

1952 ◽

Vol 24 (3) ◽

pp. 127-134

Author(s):

Armi Kaila ◽

Pertti Kivinen

Keyword(s):

Nitrogen Content ◽

Soil Nitrogen ◽

Nitrate Nitrogen ◽

Soil Samples ◽

Mineral Nitrogen ◽

Aggregation State ◽

Water Stable Aggregates ◽

Mineral Soils ◽

Simultaneous Immobilization ◽

Properties Of Soil

In the experiments reported above the effect of organic material upon the aggregation of soil particles and the simultaneous immobilization of mineral nitrogen by microorganisms were studied. The relative amount of water-stable aggregates larger than 0.5 mm in diameter was considered to indicate the aggregation state of the soil samples. Probably, somewhat different results were obtained if the crumb formation had been determined by some other method, but it is not sure that these would have been more reliable. Since the incubation of soil samples were performed under aerobic conditions, and all the samples were mineral soils, it seemed justifiable to take the nitrate-nitrogen content of the soil samples to characterize the amount of mineral nitrogen in them. On the basis of the results the general conclusion may be drawn that the more favourable the conditions are for the development of an active and large microflora in the soil, the more intensively the crumb formation and the immobilization of nitrogen takes place, but also the destruction of aggregates begins the more rapidlv. This appeared to be true with regard to the indigenous fertility of soil as well as to the fertilization. Liming, however, did not improve the conditions in these experiment, probably due to the rather slight acidity of the soil samples used. Under otherwise similar conditions the larger amount of straw produced larger amount of aggregates, but the differences in the nitrate-nitrogen content of soil in the presence of various amounts of straw were neglibigle. Generally, the degree of immobilization of soil nitrogen seemed largely to depend on the properties of soil and on other environmental conditions, and nitrogen applications, theoretically enough for the needs of microorganisms that decomposed the straw, could not always prevent an intensive absorption of soil nitrogen. The crumb formation appeared to need mere energy-yielding material than the immobilization of nitrogen, or the destruction of crumbs occurred more rapidly than the nitrification of microbiologically bound nitrogen.

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