Chemical renovation of grassland.

Abstract

Till recently the new practical prospects opened up by chemical grassland renovation were very few: the old sward was inadequately killed, seedbed preparation required rather intensive soil tillage and the method was expensive. The construction of a new type of rotary cultivator has removed many drawbacks of the earlier method. The Lely machine, rotating oppositely to the direction of travel, buries sod fragments beneath a layer of fine soil thus creating a good seedbed, and applies fertilizers, reseeds and rolls the soil all in one operation. Chemical renovation might be applicable in fields infested with weeds hard to control mechanically, such as Elytrigia [=Agropyron] repens, Deschampsia cespitosa and Festuca arundinacea and on steep hills, stony soils, etc. A. repens and D. cespitosa, however, are relatively resistant to paraquat. Sodium chlorate (98% a.i.) at 150-200 pounds per acre, applied during active growth, has given much better results against D. cespitosa and TCA is better against A. repens. Dalapon may also be used to control A. repens; it is applied at 20-25 kg/ha to regrowth in July/August and incorporated 10 days later by the Lely rotary cultivator before reseeding. A. repens is suppressed by the combination of herbicide, burial and competition from the new sward.-P.K. (Abstract retrieved from CAB Abstracts by CABI’s permission)