Losses from cattle faeces during chemical analysis

1974 ◽  
Vol 14 (71) ◽  
pp. 716 ◽  
Author(s):  
L Falvey ◽  
A Woolley
Keyword(s):  
Dry Matter ◽  
Nitrogen Loss ◽  
Routine Method ◽  
Drying Time ◽  
Sample Digestion ◽  
Faecal Material ◽  
Kjeldahl Method ◽  
Cattle Faeces ◽  
Nitrogen Contents

The effects of drying temperature and method of sample digestion on the determination of nitrogen and dry matter in the faeces of cattle grazing pastures of two different nitrogen contents were examined. Nitrogen loss varied from 8 to 20 per cent depending on the temperatures and associated length of drying time. The variation in the loss between samples from animals grazing the two pastures was small, tending to be higher for the samples taken from animals grazing a higher nitrogen pasture. Sample digestion by the H2SO4-H2O2 method was found to be as satisfactory as the micro-Kjeldahl method. Drying at 100�C for 24 hours gave the least loss of nitrogen. This procedure in conjunction with the H2SO4-H2O2 , digestion is proposed as a routine method for determination of nitrogen in faecal material.

AN EVALUATION OF NITROGEN SOIL TEST METHODS FOR ONTARIO SOILS

1966 ◽  
Vol 46 (2) ◽  
pp. 185-194 ◽  
Author(s):  
J. A. Smith
Keyword(s):  
Soil Nitrogen ◽  
Dry Matter ◽  
Nitrogen Availability ◽  
Test Methods ◽  
Soil Test ◽  
Soil Nitrogen Availability ◽  
Available Nitrogen ◽  
Nitrogen Contents ◽  
Total Soil Nitrogen

Several methods for providing an index of the availability of soil nitrogen were evaluated by relating laboratory soil test values to yields of dry matter and uptake or nitrogen by orchardgrass in the greenhouse. Determination of soil organic matter or total soil nitrogen contents was relatively ineffective. Available nitrogen initially present in the soil at sampling time, extracted by several different methods, was superior to measurements of nitrogen released upon incubation. The nitrate form of nitrogen, either initially present or released upon incubation, served as a better index of soil nitrogen availability than the ammonium form. Inclusion of initial nitrates and nitrates released upon incubation as independent variables in a multiple regression resulted in the highest correlation with total nitrogen uptake. In the three incubation methods evaluated, discarding the initial nitrogen content of the soil, as is commonly done, severely reduced the validity of the tests as measures of nitrogen availability.

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