Research from G.X. Pu and Co-Researchers in the Area of Nitrogen Described
2012 MAY 3 - (VerticalNews.com) -- According to the authors of recent research published in the journal Soil Research, "One major benefit of land application of biosolids is to supply nitrogen (N) for agricultural crops, and understanding mineralisation processes is the key for better N-management strategies. Field studies were conducted to investigate the process of mineralisation of three biosolids products (aerobic, anaerobic, and thermally dried biosolids) incorporated into four different soils at rates of 7-90 wet t/ha in subtropical Queensland."
"Two of these studies also examined mineralisation rates of commonly used organic amendments (composts, manures, and sugarcane mill muds). Organic N in all biosolids products mineralised very rapidly under ambient conditions in subtropical Queensland, with rates much faster than from other common amendments. Biosolids mineralisation rates ranged from 30 to 80% of applied N during periods ranging from 3.5 to 18 months after biosolids application; these rates were much higher than those suggested in the biosolids land application guidelines established by the NSW EPA (15% for anaerobic and 25% for aerobic biosolids). There was no consistently significant difference in mineralisation rate between aerobic and anaerobic biosolids in our studies. When applied at similar rates of N addition, other organic amendments supplied much less N to the soil mineral N and plant N pools during the crop season. A significant proportion of the applied biosolids total N (up to 60%) was unaccounted for at the end of the observation period. High rates of N addition in calculated Nitrogen Limited Biosolids Application Rates (850-1250 kg N/ha) resulted in excessive accumulation of mineral N in the soil profile, which increases the environmental risks due to leaching, runoff, or gaseous N losses," wrote G.X. Pu and colleagues.
The researchers concluded: "Moreover, the rapid mineralisation of the biosolids organic N in these subtropical environments suggests that biosolids should be applied at lower rates than in temperate areas, and that care must be taken with the timing to maximise plant uptake and minimise possible leaching, runoff, or denitrification losses of mineralised N."
Pu and colleagues published their study in Soil Research (Estimating mineralisation of organic nitrogen from biosolids and other organic wastes applied to soils in subtropical Australia. Soil Research, 2012;50(2):91-104).
For additional information, contact G.X. Pu, Queensland Dept. of Employment Econ Dev & Innovat, Kingaroy, Qld 4610, Australia.
The publisher's contact information for the journal Soil Research is: Csiro Publishing, 150 Oxford St, PO Box 1139, Collingwood, Victoria 3066, Australia.
Keywords: City:Kingaroy, Country:Australia, Region:Australia and New Zealand
This article was prepared by VerticalNews Agriculture editors from staff and other reports. Copyright 2012, VerticalNews Agriculture via VerticalNews.com.