Agriculture Reference
In-Depth Information
wheat straw, yard waste, and used cooking oil [11]. The rapid decomposi-
tion and synchrony of the crop residue N mineralization rate relative to the
organic C amendment (OCA) decomposition suggested promise for fi eld
application [11].
Even though a reduced potential for N losses may result if the period
of N immobilization coincides with periods of high risk for N losses in the
fi eld, it is necessary to assess potential effects of OCA on the subsequent
crop. Early- rather than late-season N fertilizer input is recommended to
achieve a desired yield goal for spring wheat (
Triticum durum
L.) produc-
tion [27]. Therefore, if N immobilization due to the OCA after cole crop
harvest is not followed by re-mineralization early enough in the spring
wheat growing season, a negative effect on spring wheat yield could re-
sult. Conversely, if N mineralization is synchronous with spring wheat N
demand, then N use effi ciency may be enhanced.
A pattern of N immobilization followed by re-mineralization has been
found in previous laboratory [11] and fi eld [26] research after the OCA of
used cooking oil. However, other researchers did not observe re-mineral-
ization in the subsequent spring after autumn incorporation of cereal straw
or green compost with caulifl ower crop residue [12]. Research has found
corn, lettuce, or leek production to be unaffected by the previous autumns'
application of oily food waste [16], cereal straw or waste compost [12],
respectively. Thus, it may be possible to reduce potential N losses during
periods of high risk for N losses by applying an OCA, without negatively
affecting the subsequent crop.
In addition to the environmental impacts of N management practices,
consideration must be given to the economic impacts. Some studies have
found a trade-off to exist between environmental and economic benefi ts
because practices that reduced N losses did not have favorable economic
outcomes in vegetable production [28,29]. Other studies have found an
overlap for the optimal environmental and economic outcomes [30,31].
Thus, ambiguity exists in the literature with respect to the economic im-
pacts associated with management practices for reducing N losses. Re-
gardless, the economic implications of proposing a better management
practice to minimize N losses should be evaluated.
Therefore, the objective of this fi eld study was to evaluate the effects
of three different OCAs of wheat straw (OCA-straw), yard waste (OCA-
