Nitrogen Mineralization of Two Manures as Influenced by Contrasting Application Methods under Laboratory Conditions

Abstract

The decomposition and the associated nitrogen (N) dynamics of organic N sources are affected by their contact with soil. While several authors have examined the effect of surface application or incorporation of crop residues on their decomposition rate, less information is available about the relationship between the placement of animal manure and their N mineralization rate. This study investigated the influence of chicken manure and cattle manure placement on soil N mineralization. The manures were incorporated or surface applied at 175 mg N kg −1 , and N release was periodically determined over 56 days by measuring inorganic N [nitrate (NO 3 − ) N and ammonium (NH 4 + ) N] in a 2 M potassium chloride (KCl) extract at a ratio of 1:10 (w/v). Results indicated that the control soil released a maximum of 64 mg N kg −1 soil at day 21, a sixfold increase over the initial concentration, which indicates its substantial mineralization potential. Manure treatments showed an initial increase in net NO 3 − -N content at the start of the experiments (until day 7) before an extended period of immobilization, which ended at day 21 of the incubation. A small but positive net N mineralization of all manures was observed from 28 days of incubation. At each sampling time, the mean mineral N released from the control was significantly less (P < 0.01) than surface-applied chicken manure, incorporated chicken manure, and surface-applied cattle manure. Treatments exceptions were at days 21 and 28 where N immobilization was at its peak. In contrast, incorporation of cattle manure showed a different N-release pattern, whereby the mineral N amount was only significantly greater than the control soil at days 42 and 56 with 84 and 108 mg N kg −1 soil respectively. Incorporation of chicken manure and cattle manure did not favor nitrification as much as surface application and cattle manure caused a much greater immobilization when incorporated than when surface applied.

Do plant secondary metabolite‐containing forages influence soil processes in pasture systems?

“…This may suggest nitrification inhibition from treatments with feces of both diets (CT‐containing sainfoin and saponin‐containing alfalfa). Our results support other soil manure incubation studies showing initial immobilization of N with feces additions (Abbasi, Hina, Khalique, & Khan, 2007; Baitilwake et al., 2012; Probert, Delve, Kimani, & Dimes, 2005). Lower NO 3 in both feces treatments could be explained simply by fecal manure having more recalcitrant substrate which is digested (mineralized) more slowly, releasing available N more gradually.…”

“…From the beginning (day 0) of the incubation study to the end (day 56), total N means in all treatments increased (p = .0003) from 1.10 to 4.26 mg g −1 , yet there were no differences between treatments (p = 1.0), nor interaction effects (p = .92). Our observed increase in N over the incubation study is consistent with other incubation studies (Abbasi et al, 2007;Baitilwake et al, 2012), showing an overall increase in total N.…”

“…This may suggest nitrification inhibition from treatments with feces of both diets (CT-containing sainfoin and saponincontaining alfalfa). Our results support other soil manure incubation studies showing initial immobilization of N with feces additions (Abbasi, Hina, Khalique, & Khan, 2007;Baitilwake et al, 2012;Probert, Delve, Kimani, & Dimes, 2005). Lower NO 3 in both feces treatments could be explained simply by fecal manure having more recalcitrant F I G U R E 4 Incubation study -Main effect means and standard error bars from NH 4 results from cattle feces additions from two different diets of either CT-containing sainfoin or saponin-containing alfalfa (without tannins), and a control without the addition of feces, measured eight times over 56 d substrate which is digested (mineralized) more slowly, releasing available N more gradually.…”

Effect of Organic Fertilizers on Nitrate Accumulation in Vegetables and Mineral Nitrogen in Tropical Soils of Morogoro, Tanzania

“…The observation that CHM led to more accumulation of nitrate in CC and AM than CAM at the first sampling could be explained by the slower release of N from CAM compared to CHM, as was observed in previous mineralization experiments under laboratory conditions (Baitilwake et al ., 2010). Indeed, the current results affirm further that N sources affect accumulation of nitrate in CC and AM plants at first sampling.…”

Optimal Placement of Meat Bone Meal Pellets to Spring Oats

“…If the fertilizer is instead concentrated to narrow bands in the soil, microbial access to carbon and nitrogen, and thus nitrogen immobilization, will be more limited. Baitilwake et al (2012) found greater immobilization and nitrification after soil incorporation than surface application of chicken and cattle manure. However, Delin and Strömberg (2011) did not find any differences in net mineralization of nitrogen between surfaceapplied and incorporated chicken manure and cattle slurry, as long as the manure was kept in concentrated lumps, although when the manure was mixed with a larger soil volume both net immobilization and nitrification increased.…”