Soil Problems In Fiji

There's Plenty of Limestone—Why Not Use It?

By Theo W. Rioz, of Navai

EARLY in October, 1945, I submitted to his Excellency the Governor of Fiji an article on soil exhaustion and erosion in Fiji. About the middle of December, 1945, I received a letter from the Colonial Secretary, which stated that the article had been received and read with interest, and that whilst it was im possible to agree with my criticism of the Agricultural Department, it was recog nised that much soil exhaustion and ero sion had taken place, and that a great deal had yet to be done.

Accompanying the Colonial Secretary’s letter were two reports which, it was hoped, would be of interest to me. One was by Professor Shephard and the other by Professor Paterson and Dr. Dodds.

Professor Shephard’s report was ex tremely interesting in its revelation of the immense area he covered and the tre mendous amount of data which he got to gether and collated into a report during the very sort time which he devoted to his investigations; beyond that it appears to be of little interest. He tells us nothing that we did not already know.

The professor gives me the impression that he felt that a job had been “wished” on him, and that he had to say something to justify his commission: so he recom mended the adoption of a programme which, to carry out, would strain the financial resources of a much larger coun try than Fiji.

THE Paterson-Dodds’ report is, I think, a much more valuable document, be ing distinctly more practical in its

recommendations and fundings; three of these recommendations strike me as being particularly sound: • The District Agricultural Officers should put in the bulk of their time in the field giving advice and demonstrations on and in good farming methods. • More internal roads should be built.

It is to be feared that if such a road building programme, as outlined by them, is not adopted, all attempts to improve the agricultural conditions of the Colony will end in stultification. • Ground lime-stone or coral sand should be made available for applying to the land. They also mention burnt lime.

Like most tropical soils the bulk of those in Fiji are deficient in lime con tent and are in consequence highly acid.

Therefore, it is necessary to apply lime by artificial means, and of the three types mentioned in the report I prefer coral sand or ground limestone.

Because of the slowness of the avail ability of their lime content, burnt lime certainly gives more rapid results, but it leaches out of the soil very quickly with the heavy rains experienced in Fiji, thus requiring more frequent application. An initial application of 2 tons of coral sand or ground limestone would last for from 4 to 5 years, depending on what use the land was being put to; intense cultiva tion would, of course, use up the lime content more rapidly than would stock grazing.

Coral sand is particularly useful be cause of certin fertilising agents it con

tains. But it must be borne in mind that lime is not in itself a fertiliser: its function is to check soil acidity, improve the mechancilal condition of the soil and make available to the plant certain foods which are stored in humus.

LIME will not produce crops if the soil is devoid of humus, but it will make it possible to grow humus-forming crops, such as clovers, beans, peas and lucerne, all of which store nitrogenous

bacteria in root nodules. These plants should be either ploughed under at the flowering stage or grazed off by stock; after expiry of the first four years an application of from 15 to 20 cwt. of ground limestone per acre, every three or four years, will maintain the lime content at a satisfactorily high level.

We have on this island of Viti Levu an almost inexhaustible supply of limestone.

The Colonial Sugar Refining Co. used lo quarry limestone only a few miles out side of Labasa, on Vanua Levu, and burn it at Labas for use in its sugar mill there so it is only reasonable to suppose that there are other sources of supply on that island.

On the south-west coast of Viti Levu, there is a veritable mountain of lime stone, at Tau. This is where the Em peror Gold Mining Co. burns all the lime it requires for its gold-extracting opera tions. The amount of rock that com pany will require is but an infinitesimal portion of the whole.

A comparatively inexpensive plant could be installed to quarry and grind the stone for agricultural use. This mountain is less than three-quarters of a mile from the Queen’s Road; less than II miles from the C.S.R. Co.’s tramway; and it is not more than H miles to an inlet of the sea where lighters could lie to load the ground limestone. If that is insufficient to last more than 1,000 years, there is still Malaquereqere Freehold within five miles of Navunasalu; and after the next 1,500 years there would still be left the limestone hills at Nabaka, up the Na Sigatoka River, to draw on.

Then there are the marble outcrops on the Upper Rewa River which could be utilised to produce lime for agricultural purposes. Pure marble is being mined and ground for that purpose in the Nel son district of NZ. Ground limestone could be made available to the agricul turalist and pastoralist at prices well within those indicated in the Paterson-* Dodds’ report—namely, 12/- per ton.

CORAL sand, as I mentioned before, is useful because of elements it con tains other than lime; but there are certain difficulties in obtaining coral sand. One is that one source of supply* is the sea beach, and to remove it thei Land Board would have to be approached for permission. If one was operating by

water, one would have to own or be able to hire lighters and launches.

If one wished to operate from the land side, one would have to, in most cases, negotiate with the natives for a right of-way to the beach, as well as construct a road. Added to this would be the pos sible high salinity of the sand. The coral sand best suited for application to the land appears to be the semi-fossilised type, which usualy lies some distance in land from the high-water mark. This has to be excavated.

The C.S.R. Co. has been obtaining its l supplies of sand by means of a mech anical “Pyman” excavator, from an area of land known as Dreketi, on the south ern side of the Saweni bathing resort, in the Lautoka district. By the time that company’s requirements are satisfied, it will have wiped out 100 acres or more of good cane land. So it is hardly reas onable to ask that organisation to hand out coral sand which it will require itself.

The only other areas of this type of de posit are: one at lako, on J. P. Bayly’Si estate, and he would be —I imagine— most unlikely to destroy a valuable piece of property for the sake of providing lime for other people.

There are areas between Yako and Cuvu, but these are all under sugar cane. There are others between Cuvu and Na Vuna Niu point; one is on the Korolevu Estate, but one can hardly visualise the Hon. H. H. Ragg agreeing! to having his property despoiled in order to relieve the Government of the re sponsibility of making lime available. The other areas have all, without exception, got Fijian villages situated on them. The answer to the lime requirements would seem to be Tau.

SOME of 'your readers might be in terested to know the composition and function of humus.

Generally speaking, humus is composed of decaying leaf moulds and other or ganic matter, such as roots and plants.

Humus provides a home for the micro organisms which release surplus materi als not required by themselves, and make them available to the plants.

The rate of mineralisation depends on the chemical composition of the organic: matter. If it is rich in nitrogen, phos phorous, lime, magnesium, etc., then both soil bacteria and growing plants get their share; but if the humus contains only small amounts of these minerals, then the microbes take the lot, leaving the plants to starve.

This is why young, green manures pro vide more nutriment than mature, strawy residues. Recent work has shown that in the organic matter is stored also the trace elements; copper, zinc and boron, all of which are required by plants in minute quantities.

So the aim of every agriculturalist and pastoralist should be to get plenty of humus into the soil and, with the aid of lime, make the plant foods contained therein available to the useful plants.

IAM at a loss to understand why it should have been deemed necessary to bring men all the way from Trini dad to tell us what we already know, and to solve problems which a committee of hard-headed practical farmers, with the local Director of Agriculture as technical adviser, could have solved.

Nor can I understand why Fiji should be tied agriculturally to Trinidad, which colony is situated in a different hemis phere, with a climate and soil quite dif ferent from thoSe of Fiji. If the state-' ments of various eminent men who, from time to time, lecture before the Royal Empire Society on Trinidad and other* West Indian Colonies are to be accepted as correct—and I am sure that they are

—Trinidad has still a long way to go before it has solved its own agricultural and economic problems. In the light of those lecturers’ utterances, Trinidad is a century behind Fiji in most things.

Admittedly, members of our agricul ture department should be able to hold consultations with members of some other department of tropical agriculture.

This being so, what is wrong with Fiji, tying up with the Queensland Depart ment of Agriculture? Queensland pro duces everything that Fiji produces— with the sole exception of copra, and that is produced in the Federal-controll£d Territory of New Guinea.

Queensland’s climate and soil are similar to those of Fiji, and the agricul tural and pastoral activities are the same; so what would be better than an arrangement whereby there could be an exchange of information and officers be tween the two countries?

The distance between Fiji and Queens land is but a fraction of that which lies between Fiji and Trinidad, whilst the* cost of transporting men to and froi would be a mere bagatelle by compari son. Such an arangement should be of benefit to both countries, particularly to Fiji.

Mr. W. A. Anderson has been appointed Resident Officer of the Queensland In surance Co., Ltd., in the Territories of New Guinea and Papua. He recently has taken up his residence in Port Moresby where he has offices in the Burns Philp building. He is a returned Serviceman; and, prior to the war, he was an inspec tor attached to the Townsville branch of the company.