Reduced tillage systems: evaluation of the influence of tillage and fertilizer management on soil quality, crop productivity and economic sustainability
Results from the first two years of a four year field study conducted on two soil types to evaluate the effect of nitrogen source, timing and placement on canola and durum, under conventional and reduced tillage systems indicated that yield tended be higher under conventional tillage than zero tillage, and was influenced by source, timing and placement of fertilizer N.
IPNI-1993-CAN-MB6
24 May 2001
Justification
- Efficient fertilizer management is critical, not only in ensuring economic viability in crop production, but also in maintaining long-term environmental quality and sustainability of the soil resource. Efficient applications of fertilizers which are in balance with the nutrient requirements for crop production contribute to maintenance or improvement in soil quality, by increasing residue cover and return of organic matter to the soil. This aids in reducing erosion and in maintaining organic matter levels within the soil. The increased organic residues produced with proper fertilizer management act as nutrient reserves for enhanced biomass production. Nitrogen fertilizer, when used as recommended by soil testing, has been shown to reduce nitrate leaching by encouraging effective root development and crop utilization of N from the soil profile. However, excessive N fertilization or the use of ineffective fertilizer application techniques are not only economically inefficient, they can also create environmental problems, by nitrate leaching into the groundwater or emission of nitrous oxide, nitric oxide or ammonia to the atmosphere.
Efficient fertilizer management considers four major factors:
1) Rate of application
2) Timing of application
3) Placement of fertilizer
4) Source of fertilizer
Optimum rate, timing, placement and source of fertilizer nutrients is influenced greatly by the soil type, climatic conditions, tillage systems and type of crop grown. Other management considerations specific to the particular farming unit, such as equipment availability, time and labor constraints through the growing season, and taxation and cash flow situation may also strongly impact on a producer's fertilizer management decision. Therefore, it is important for a farm manager to have comparative information on a range of application techniques and fertilizer sources under varying soil, climatic and management situations, in order to select the fertilizer management package best suited to his particular situation.