Soil NO emission from organic and conventional cotton farming in Northern Tanzania.

The effort to increase the sustainable supply of food and fibre is challenged by the potential for increased greenhouse gas (GHG) emissions from farming systems with intensified production systems. This study aimed at quantifying soil NO emissions from smallholder organic and conventional cotton production practices in a semi-arid area, Meatu, Northern Tanzania. Field experiments were conducted to quantify NO emissions under (i) current practices with organic (3 Mg ha farmyard manure (FYM)) and conventional (30 kg mineral N ha) cultivation; (ii) a high input practice with organic (5 Mg ha FYM) and conventional (60 kg mineral N ha) cultivation; and (iii) an integrated practice with organic (3 Mg FYM + legume intercropping) and conventional (30 kg N + 3 Mg ha FYM) cultivation.

Effect of feeding practices and manure quality on CH and NO emissions from uncovered cattle manure heaps in Kenya.

Countries in sub-Saharan Africa (SSA) rely on IPCC emission factors (EF) for GHG emission reporting. However, these were derived for industrialized livestock farms and do not represent conditions of smallholder farms (small, low-producing livestock breeds, poor feed quality, feed scarcity). Here, we present the first measurements of CH and NO emissions from cattle-manure heaps representing feeding practices typical for smallholder farms in the highlands of East Africa: 1) cattle fed below maintenance energy requirements to represent feed scarcity, and 2) cattle fed tropical forage grasses (Napier, Rhodes, Brachiaria).

Land use affects total dissolved nitrogen and nitrate concentrations in tropical montane streams in Kenya.

African tropical montane forests are facing fast and dynamic changes in land use. However, the impacts of these changes on stream water quality are understudied. This paper aims at assessing the effect of land use and physical catchment characteristics on stream water concentrations of dissolved organic carbon (DOC), total dissolved nitrogen (TDN), nitrate (NO-N) and dissolved organic nitrogen (DON) in the Mau Forest, the largest tropical montane forest in Kenya.

Ammonia volatilization after surface application of laying-hen and broiler-chicken manures.

Ammonia (NH) losses after field application of animal manure are affected by manure characteristics. The objectives of this study were to quantify NH losses from poultry manures obtained from varied handling and storage systems commonly found in eastern Canada and to relate NH emissions to manure characteristics. We measured NH volatilization using wind tunnels for 22 d after soil-surface application of seven solid poultry manures originating from farms varying in production type (laying hens and broiler chickens) and in storage duration and conditions.

Ammonia volatilization and nitrogen retention: how deep to incorporate urea?

Incorporation of urea decreases ammonia (NH) volatilization, but field measurements are needed to better quantify the impact of placement depth. In this study, we measured the volatilization losses after banding of urea at depths of 0, 2.5, 5, 7.

Nitrous oxide emissions from clayey soils amended with paper sludges and biosolids of separated pig slurry.

Wastes from animal production and from the paper industry are often used as amendments to agricultural soils. Although data exist on the impacts of raw animal wastes on NO production, little is known regarding the effects of paper wastes and biosolids from treated animal waste. We measured NO emissions for two consecutive snow-free seasons (mid-May through the end of October) from poorly drained clayey soils under corn ( L.

Nitrous oxide emissions respond differently to mineral and organic nitrogen sources in contrasting soil types.

The use of various animal manures for nitrogen (N) fertilization is often viewed as a viable replacement for mineral N fertilizers. However, the impacts of amendment type on NO production may vary. In this study, NO emissions were measured for 2 yr on two soil types with contrasting texture and carbon (C) content under a cool, humid climate.