Author(s)

Nguyen Thanh Binh^1,2, Hoang Thi Quynh³, Kazuto Shima¹

¹Department of Environmental Ecology, Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan.
²Department of Soil Agro-Chemistry, Faculty of Agronomy, Nonglam University, Ho Chi Minh City, Vietnam.
³Vietnam Institute of Meteorology, Hydrology and Climate Change (IMHEN), Hanoi, Vietnam.

Combining compost with sufficient chemical N fertilizer (CF) in agricultural lands is a popular practice to reduce the amount of inorganic nitrogen and accumulation of non-nutrient constituents in soils. A pot culture experiment was conducted to study the effects of 130 mg N of either solids waste compost (Scomp) or biosolids waste compost (Bcomp) complemented with 130 mg (CF, 1N) and 260 mg·N·pot^-1 (CF, 2N) as ¹⁵N labeled (NH₄)₂SO₄ (13.172 atom %) on growth and N uptake by Italian ryegrass. A separate soil incubation without plants was set up by only blends of Scomp and CF. The results from pot culture experiment show that total plant biomass and N uptake from Bcomp were significantly higher than Scomp alone. Scomp combined with CF improved yield and N uptake over those of Scomp alone. For Scomp + 1N treatment, plant nitrogen uptake derived from compost and CF accounted for 29% and 56% of added N from Scomp and CF, respectively. The incubation study indicates that 16.08 - 29.62 mg·N·kg^-1·soil·day^-1 from inorganic-N were immobilized into organic pools, while only 0.40 - 0.66 mg·N·kg^-1·soil·day^-1 from organic-N were mineralized to inorganic pools. Because a part of additional N could be tied up in organic form, combining solids compost with chemical N fertilizer therefore need to consider the effective use of compost-N.

Solids, Biosolids Compost, ¹⁵N Nitrogen Uptake, Mineralization, Immobilization

Binh, N. , Quynh, H. and Shima, K. (2015) Effect of Composts Combined with Chemical N Fertilizer on Nitrogen Uptake by Italian Ryegrass and N Transformation in Soil. Journal of Agricultural Chemistry and Environment, 4, 37-47. doi: 10.4236/jacen.2015.42004.