Topics : Soil Fertility for Forage Crops : Establishment
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Introduction to Soil Fertility for Forages
Soil fertility management for forage crops is a continuous process that begins well before the forage crop is established. In the pre-establishment phase, the soil conditions are adjusted to provide optimum soil fertility when the crop is established. The fertility program during the establishment phase should deal with last minute, small adjustments in soil fertility and any requirements such as a starter fertilizer for getting the plants established. After the crop is established, the fertility program should focus on maintenance of good fertility levels in the soil for the life of the forage stand.
If the pre-establishment fertility goals have been met, few things need to be taken care of at the establishment phase (Figure 1). In the establishment phase, the primary goals of soil fertility management are to fine tune the soil pH or nutrient levels and to assure that the conditions are optimum to establish the crop.
Fig. 1. Soil Fertility management time-line for corn-forage rotation.
When only a small amount of limestone is needed to make an adjustment in the soil pH, it should be applied after primary tillage and worked into the surface before planting. If a large amount of limestone is needed, the lime application should be split and some mixed deep into the soil with primary tillage, and the rest should be applied after primary tillage but worked into the surface. These measures will give the best distribution of limestone and will assure that the surface pH where the seedlings are developing will have a better pH level.
If a soil test taken just before establishment indicates the need for additional fertilizer, the size of the requirement will determine how this should be applied. For instance, if the pre-establishment goals have been completely met and there is no soil-test recommendation, there usually is no need to apply any fertilizer. If the soil test recommends addition of only a small amount, the recommend amount can be banded at planting or broadcast on the soil surface. But, if the soil-test indicates a need for a large amount of fertilizer, the best approach would be to split the fertilizer application with the bulk of the nutrient needs met with plow-down fertilizer or manure. A small amount of the total fertilizer requirement, such as 20-40- 40 per acre, should be banded at planting or applied to the surface to meet the immediate needs of the crop as it is established.