LIMONITE

Waipa Post, Volume 45, Issue 3251, 5 November 1932, Page 6

LIMONITE

EFFICACY AS LICK OR DRENCH. In the course of an interesting lecture on mineral deficiency and the use of limonite, by Mr C. R. Taylor, of the Chemistry Division of the Department of Agriculture, the lecturer opened by giving details concerning the geological map of the central part of the North Island of New Zealand. He said there are eight pumice soil-forming showers concerned, viz., Egmont, Mairoa, Taupo, Ngauruhoe, Tongariro, Kaharoa, Tarawera, and Tirau. Of these eight pumice showers only two, Taupo and Kaharoa, give rise to the condition in stock commonly known as bush sickness or iron hunger, the Kaharoa being the worst of the two. All other pumice showers are fairly high in available iron, and, consequently stock are not troubled with iron malnutrition. The Taupo shower was ejected from what is now known as Lake Taupo and it is estimated by the geologists that something like five and a-half cubic miles of material was ejected from that source. The area covered by the shower occupies, roughly, 8600 square miles or 5,500000 acres, and only a comparatively small part is under cultivation, largely owing to the fear of iron hunger. The Atiamuri experiment of feeding sheep with limonite was carried out on this shower country. The Kaharoa shower is a more recent one, erupted from some source just south of Lake Rotoiti, and extends from north of Tauranga to east of Whakatane, and inland to Te Whaiti.

The limonite treatment, as carried out with sheep at Atiamuri, was specially interesting as demonstrating the efficacy of supplying stock on iron-deficient country with sufficient iron to maintain good health. There were three groups of fifty sheep each, which grazed in rotation on five paddocks. The only difference in treatment was that the No. 1 group had limonite and salt, mixed on a 50/50 basis. The No. 2 group was given iron ammonia citrate with salt, but these sheep would not take sufficient quantity to keep them in good health, owing to the bitter taste of the citrate. The No. 3 group provided the control to the other two methods of treatment and were fed on the grass pasturage without any special treatment. Each group was weighed monthly and the No. 1 group showed a progressive increase in weights for the duration of the experiments, while the two other groups showed a marked decline in weights. The average individual weights of the three groups were well within 81b. at the commencement of the experiment, indicating that each group was as near alike as it was possible to make them. The experiment commenced in May, 1931, and by March, 1932, the average individual difference in weight between No. 1 and No. 3 groups was 561 b.

The No. 1 group produced 100 per cent of lambs. The No. 2 group 76 per cent and the No. 3 group 86 per cent. The lambs of No. 2 and No. 3 groups were all dead by the end of February, while of the lambs of the No. 1 group there are still 45 out of the original 50—five having been bogged in a swamp—and their average individual weight on August 20, 1932, was over 1001 b. live weight. The limonite, or hydrated iron oxide, is obtained from quarries at Whangarei and is ground to a fine powder and mixed with the same quantity of salt to form the lick. It is being used very extensively as an iron tonic over a large part of the North Island. The No. 1 and No. 2 groups of sheep at Atiamuri had access to the licks at all times. Limonite may be used as a drench in severe cases. The dose for a sheep is one teaspoonful in two ounces of water, and for cattle one heaped dessert spoonful in a quart of water. The limonite is not soluble and must be shaken up just prior to the

drenching process. The use of limonite was quite beyond the experimental stage as a lick and a drench, ( but no results are obtainable by use in top-dressing. The lecture was well illustrated by lantern slides which depicted the extensive areas affected by the vai'ious ash showers; the experimental paddocks on which the sheep were grazed on the Whangapoa station at Atiamuri; No. 1, No. 2 and No. 3 groups of ewes and lambs; lick troughs for cattle and sheep; cows and calves treated with limonite, the condition of the cattle reflecting the efficacy of the treatment. Figures were quoted by Mr Taylor showing very appreciable increases in the yields from dairy cows which were given limonite. In reply to questions, Mr Taylor said limonite could be added to ensilage and also fed out with hay. Other questions bearing on the use of various fertilisers were asked and answered. VISITOR MUCH IMPRESSED BY TOKOROA. A recent visitor to Putaruru, Mr G. Kent, secretary of the Whakatane Herd testing Association, was loud in his praise Of limonite as a tonic agency. Speaking of what is known as the Atiamuri experiment, Mr Kent said that the sceond crop of lambs were excellent. Where bush sickness was prevalent the farmers were inclined to los e heart, but now that limonite has been proved to be capable of overcoming the bush sickness, farmers are regaining heart, and consequently their farms show a marked improvement. In the Rangataiki district limonite was used as a tonic and it has a marked effect on the herds. It was being used more and more, and gave a general toning up to the stock. Mr Kent said he was impressed by what he saw at Tokoroa. There was no doubt that li-. monite meant a big thing for that district.