Organic manures and grasslands

Abstract

In fertilisation programmes emphasis is usually given to the mineral elements and organic factors of the soil are neglected. Soil productivity is a function of both the inorganic and organic status of the soil and the latter warrants greater attention in Southern Africa. On the basis of the nitrogen balance in fertile, highly stocked grassland, the author discusses the improvement of less productive grasslands in lower rainfall areas. Suggested measures for improvement include subsoiling, surface treatment for better water penetration and seedbed preparation. The introduction of legumes for symbiotic nitrogen fixation and the production of supplementary feed on manured, cultivated lands are discussed as measures for the attainment of high stocking rates and improved fertility balance.

UITTREKSEL

In bemestingsprogramme word die klem gewoonlik gelê op die minerale elemente terwyl organiese faktore verontagsaam word. Grondproduktiwiteit is ‘n funksie van beide die anorganiese en organiese status van die grand en laasgenoemde regverdig meer aandag in Suidelike Afrika. Die skrywe bespreek die verbetering van minder produktiewe weidings in laer reënvalstreke op basis van die stikstof balans soos dit voorkom in vrugbare hoogbeweide weidings. Voorgestelde maatreëls vir verbetering sluit in die diep losbreek van die grand, oppervlakte behandeling vir beter indringing van water en saadbedvoorbereiding. Die insaai van penlpkante vir simbiotiese stikstofbinding en die produksie van aanvullende voer op goed bemeste lande word bespreek as maatreëls vir die verkryging van hoë veeladings en verhoogde vrugbaarheid.