DEEP DRAINAGE OF CLAYS.

Otago Witness, Issue 1476, 28 February 1880, Page 6

DEEP DRAINAGE OF CLAYS.

I am fairly overweighted by correspondence, and at seventy-seven one's powers are not quite so strong as they were in earlier days. lam a firm believer in 4ft pipe diains, from long experience, even in plastic clays, which forms part of my farm. They do discharge after rainß, aud continue to do so until the surplus water is removed. If you were to drain the land at two depths, four and two feet, tho upper drains would not, I think, run until there was more water than could pass to the lower drain, which always discharges for the longest period. I once drained at 2ft and 6ft. The upper one never discharged, except on one or two occasiona when the spring was very high and the laud full. It is like tapping a cask with two taps. The upper one would never discharge when the cask was being filled until a greater supply was put in than the lower one could carry. The filtrative or non-filtrative character of the soil is a separate matter from the diainage.. This is why open drains are required on plastic clays to relieve the seed-bed quickly. Farmers who lay then land flit on plastic clays lose th<sir money. Tho seed-bed in winter becomes sodden mud. I never saw land that would not pass water to deep 4ft drains. It is a mere question of time and avoidance of stagnation. Gravity overoomes capillarity in deep drains.— J. J. Mechi.