The effects of long-term manure application on DM yield of perennial grasses and soil chemical properties

The efficiency of systematic fertilisation with different rates of manure in a seven-field rotation was studied in a long-term trial set up at the Vezaiciai Branch of Lithuanian Agriculture Institute in 1959. Perennial grasses were grown in the 6(th) rotation. The impact of manure on dry matter (DM) yield of perennial grasses and soil agrochemical properties is discussed in the paper. The prevailing soils are loamy Albeluvisols (Ab, FAO-Unesco, 1998). The research was carried out in two field trials: 1) established in acid and 2) in limed soil. Trial treatments were as follows: 1) without manure, 2) 20, 3) 40, 4) 80 and 5) 120 t ha(-1) of manure. Manure was incorporated in two times at equal portions per rotation. Perennial grasses were grown in the third and fourth year after manure incorporation. All manure rates significantly increased DM yield of grasses (1(st) year of use) on acid soil and higher manure rates (80 and 120 t ha(-1)) on limed soil. The highest DM yield (5.33 and 5.89 t ha(-1)) of perennial grasses was obtained on the soil that was limed and was applied with the heaviest rates (80 and 120 t ha) of farmyard manure. Timothy was the dominant species (27-71%) on acid and red clover (89.7-92.7%) on limed soil. The content of mobile aluminium in acid soil declined from 117.8 to 26.8 mg kg(-1), and in limed soil it did not have any effect. Manure fertilisation increased the content of mobile potassium, phosphorus, and humus both in acid and limed soil.