A Farmer's Notebook APPLICATION OF FERTILIZERS

Southland Times, Issue 24533, 6 September 1941, Page 10

A Farmer's Notebook APPLICATION OF FERTILIZERS

DRILLS AT SIDE OF SEEDS

RESULTS FROM LATEST INVESTIGATIONS

In these days full utilization of the phosphate content in superphosphate, reverted superphosphate, di-calcic phosphate and bones allowed under I the rationing plan is of the greatest importance to farmers. The degree of success met with determines to a very large extent whether production costs can be kept at a level that will afford a farmer a reasonable profit or perhaps none at all. There are many factors that exert considerable influence upon the uptake of phosphate by plants irrespective of whether the soil contains adequate, or only partial amounts of the requirement of the crop concerned. As mentioned in last week’s notes, scientific investigations have made considerable strides during the last decade in determining means whereby farmers can avoid mistakes of the past and secure much higher crop yields from a given amount of phosphate than formerly. Control of the phosphate value of the soil by liming is one of the important advances made, and another is the correct placement of fertilizer in the soil.

Applying fertilizer in the right place is as important as applying the right analysis or the right amount. This highly important fact was largely overlooked by soils investigators until the last 15 years. Even today it is not fully appreciated by farmers. Many continue to use methods and machines whose low efficiency has been clearly demonstrated. AMERICAN RESEARCH In the United States of America the placement of fertilizers in the soil for various crops has been extensively studied for a long period, and the following important conclusions have been arrived at: —(1). That for crops sown in rows the most effective use of fertilizer is obtained when it is distributed in two bands on either side of the seed; (2). that the movement of fertilizer in the soil is “up and down”— down following a rain and up at times when moisture is evaporating from the surface. Numerous studies have shown that almost no lateral movement of fertilizer salts occur.

In the American Agricultural YearBook “Soils and Men” reference to sideband placement is as follows: “No 1 single fertilizer pattern has been found ■ superior with all crops and under all 1 conditions. Almost without exception, • j however, in the numerous comparisons ' | that have been made, placing the fer- ’ [ tilizer at the sides of the seed, or plant, ’ | has been most efficient? On the aver--1 age no other placement appears to be 1 reven a good second .... The general 1 superiority of side-band placement is : easily explained by the tendency of i fertilizer salts to move up and down, I but only slightly in a horizontal dii rection. The seed lies in soil free of i fertilizer, and both young roots and shoots can develop without coming into contact with an excess of fertilizer salts. A narrow band of fertilizerfree soil at the side of the seed, between it and the fertilizer band, serves to prevent damage.” , This season it is expected that a number of trials will be made with the side-band placement for swedes ’ i and turnips in particular, and a coulter specially designed for the purpose will be provided by a local firm. According to results obtained in the United States of America neither broadcasting, nor I sowing in drills immediately underI neath the seed is anything like as efl fective as the side-band placement. It will, therefore, be of considerable interest to Southland farmers to find out if the method is successful in this province. The -ummary of the Swedish investigations on the behaviour of phosphate in the soil, which was promised last week is as follows: DEPTH OF SOIL The solubility behaviour and’ the mobility of the phosphoric acid deI rived from, the superphosphate in the soil have been studied. It has been found that in a mineral soil with acid j reaction this material enters at once I into very stable compounds, and that [it moves about only very slightly in the ground water. It is, therefore, of the greatest importance to plow phosphatic fertilizers far down into the soil. The immobility of the phosphoric acid is also reflected in the vertical distribution of the phosphate in the soil. The content of plant soluble phosphoric acid in the farm soil is, therefore, always higher in the furrow than in the sub-soil and the dividing line between these two layers is very definite. In permanent meadows and pastures the phosphate content at the surface (0 to 2 inches) is very high, but it diminishes rapidly downwards, and at a depth of 2g to 4 inches the same value as in the actual sub-soil. The cultivated ground in Sweden consists to a very large extent of more or less loamy mineral soil with an acid reaction and an unsatisfactory phosphate condition. In such a soil the conditions for bringing about a satis- j factory fertility level of phosphate are usually less favourable than elsewhere because the phosphoric acid is fixed into such insoluble compounds as to make it difficult or impossible for plants to obtain any phosphorus. The only way to obtain a better fertilizing effect is to “saturate” with phosphoric acid. Most farmers are unable to purchase the large amounts of phosphate required. In order to overcome these difficulties the following expedients are recommended: (1) The soil is first fertilized with lime; (2) Thomas phosphate fertilizer or some other fertilizer having the same chemical composition is applied; (3) If superphosphate is used it should be in the granulated form only; (4) Granulated superphosphate gives the best results if it is distributed by means of a conventional drilling machine, 21 tu 4 inches deep and in rows 5 inches apart; (5) Conventional pulverized superphosphate is mixed, before being spread, with large amounts of animal manure. It is further brought out that due to the fact that the lime and phosphate conditions of the soil change considerably and irregularly from place to place, it is necessary to prepare soil maps, which show soil type, its value, and its phosphate condition, the latter factor being determined by Egner’s lactate method. The planning of anyfertilizing or liming experiments in the field should always be based on such a soil map. Finally the experimental findings are tabulated on the basis of the soil ( characteristic studied. In this way it becomes possible to prepare tables ; which can serve as a guide to farmers ' whose soils are mapped out, but who ' are unable to have experiments carri- 1 ed out on their farms. '