Performance of geotextile-gravel bed all-weather surfaces for cattle

Abstract

A cost-effective way of producing all-weather surfaces for cattle is to use a combined geotextile-gravel pad construction, which allows pavement depth to be reduced. This study sought to determine the pavement construction that would offer the least runoff, best drainage effect and highest quality runoff and drainage effluent after exposure to heavy precipitation under different manure loads in high animal density areas. The study also examined whether any pavement construction gave acceptable sealing to the underlying soil surface. Three different combinations of non-woven and woven geotextile together with two gravel fractions of 200 mm were exposed to 50 mm precipitation for 30 min and 15 kg of cattle manure under two manure regimes (manure removal and manure accumulation). Runoff, drainage effluent and leachate flow were measured and sampled in buckets as they exited their respective pipes for both regimes. The pad surface layer reduced runoff flow rate and stabilised drain flow throughout the experiments, confirming pad stability. Manure removal reduced total N, total P, chemical oxygen demand (COD) and total solid (TS) concentrations in drainage effluent. One pad construction proved better at oxidising NO 2 –N and another at trapping TS. One pad construction met the sealing liner norm to the underlying soil. The drainage effluent produced was acceptable for wetland treatment. The results show that geotextile and gravel pad constructions not only have a supporting and draining function, but also a filtering, aerating and sealing effect.