ABSTRACT
Nutrient uptake and fertilizer efficiency are also greatly affected by different tillage systems. Many researchers have identified these soil property changes and have related them to nutrient uptake and fertilizer efficiency. Nitrogen availability in no-tillage systems has received considerable attention. Thomas et al. observed nearly a 50 percent reduction in nitrate nitrogen in the surface 15 cm of soil under no-tillage. Lower mobility of phosphorus and to a lesser extent potassium often results in the accumulation of these nutrients near the surface when fertilizers are surface broadcast in no-tillage systems. Surface applications of acid forming nitrogen fertilizers often lowers the surface pH of no-tillage soils, particularly the sandy soils with low buffering capacities. Surface soil pH should be closely monitored when nitrogen fertilizers are surface applied. More frequent applications of lime at low rates may be needed, particularly on sandy soils with low buffering capacities.
