Manuring for Milk.

Horowhenua Chronicle, 29 September 1910, Page 4

Manuring for Milk.

A paper of interest to dairy farmers has just been read before the Sociotv of I'ublic Analvsts by Mir M.. J Golding, F.1.C.. F.C.S., of the Midland Agricultural and Dairy College. An interim report on an experiment commenced in Aiu'il. 1909, on manuring for milk has been issued by the College, and lormodthc substance of the paper. The experiment was designed to test the influence of superphosphate and sulphate of potash on the milk yield of the cows. Foir the purpose ol tho experiment a field of about I acres of very poor pasture, once only clay soil, was divided bv fences i lll'■ two. The two plots wore then dressed with KVwt- per acre of ground lime, and then two days afterwards one plot of two acres was given -lewt of superphosphate and l.lcwt of sulphate par acre. This piot is called " If, the untreated plot "A." Roth plots were chain harrowed, but received no ofhei treatment. Two lols of two cows were turned on to the plrds. when they remained for I I days. Instead of taking the sum total of the milk secreted on on<h of the I . days as the yield of the fortnight, the yield of the second week wa.doubled to .represent Hie yield oi th; two weeks, and the composite fat test C-. 1 ' th? last seven davs ns representing tho average quality for the fortnight. In addition to the composite fat !esf, the milk yielded on every t wolf Hi day was '•nrcfully sampled for eoninlele analysis. A' the end of the fortnight the lotwere transposed, a week allowed fo; (lie change to take effect, and thr milk uiveil dining the second w:»ek doubled as before to .represent Hit lortnight. The season exended over five months, so thai each lot of cows visited each plot five times. The first and most interesting feature of the experiment is the large decrease in yield which took place so consistently when the "lot" 'cows were moved from the treated to the untreated plot ("R" to "A"), tho fortnightly loss being in the average case 2091b5. To a certain extent this decrease "was due to the more advanced stage of tho period of lactation, but that it was due more to the poorer condition of the pasture on "A" is evidenced by the fact that when the "lot" cows were moved from "A" to "R" there was an average increase of 23ilbs in milk yield. The numerous tests for fat exhibit no special feature except, perhaps, to show that decrease in total quantity of milk is. as a rule, accompanied hy increase in tho porlentace of fat. The total yield of milk from plot "B" was 9020'JlLs. and that from plot "A" fio.'Ulbs. The excess of "R" over "A." therefore, is 3489J1 hs, which, reduced to .<irHons per acre, moans an inrtreasod yield of 8-1 gallons per n'-re. The cost of the limp being common to both plots need not bo taken into consideration, the cost of the superphosphate and sulphate of potash was 29s per acre. Consequently for tho additional expenditure of 29s wo obtain an increase of 8-llbs of milk, which. at So "or gallon, shows a oit)fit of CI 7s. T(T must be understood that tho exporimoui is not. yet completed. Tt will go on for at least another season, or'until' such time as the results show that tho effect of phosphoric and pot ass i( dressings are no longer appreciable.