WHEAT MANURING EXPERIMENTS IN THE SOUTH ISLAND, SEASON 1932-33.

New Zealand Journal of Agriculture, Volume 47, Issue 3, 20 September 1933, Page 166

WHEAT MANURING EXPERIMENTS IN THE SOUTH ISLAND, SEASON 1932-33.

• Fields Division, Department of Agriculture. The programme of wheat manuring experiments carried out by the Fields Division during the 1932-33 season comprised twenty-three trials, all of which were carried out in co-operation with farmers in Canterbury and North Otago. The season was distinctly favourable for the wheat crop generally. One experiment had to be abandoned owing to excessive lodging of the crop, while in another case data were not available owing to a misunderstanding on the part of the co-operating farmer. The methods employed in carrying out wheat-manuring trials were described in the Journal for July, 1926, and some improvements were illustrated in the April, 1929, issue. Types of Experiment, 1932-33. With the exception of three experiments laid down in districts where the effect of superphosphate was in doubt, “ no-manure ” plots were not included, and all plots received a basal dressing of super. The advantages of. using 1 cwt. of super per acre with wheat have been amply demonstrated by experimental results in the past, and it is intended to summarize the effect of super in all experiments carried out to date in a later article. The trials were designed to further investigate the use of nitrogen, and, with one exception, all experiments involved the use of different forms of —chiefly sulphate of ammonia and nitrate of soda —and different times of applications of these.

The treatments per acre for each type of experiment are shown below. . In all cases super was drilled in with the seed. The nitrogenous fertilizers were either drilled in with the seed or applied as a top-dressing in the spring.

Type A : Trials of quantities of sulphate of : ammonia and nitrate of soda, using equal weights per acre.

Treatments — (1) No nitrogen. (2) Sulphate of ammonia, 1 cwt., with seed. (3) Sulphate of ammonia, 1 cwt., top-dressed in late August. (4) Sulphate of ammonia, if cwt., top-dressed in late August. (5) Nitrate of soda, 1 cwt'., top-dressed in late September. (6) Nitrate of soda, if cwt.,- top-dressed in late September.

All these treatments received 1 cwt. of super. Sixteen experiments of this type were carried out, two of which were abandoned. In two experiments plots were included which received no phosphate, but in these trials Treatment 2 was omitted.

Type B : Trials of times of application of sulphate of ammonia and nitrate of soda, using equivalent quantities of nitrogen. Treatments—(1) No nitrogen. (2) Sulphate-of ammonia, 1 cwt., applied with seed. /i' . (3) Sulphate of ammonia, 1 cwt., applied in late August. '

(4) Nitrate of soda, 149 lb., applied in late August. (5) Sulphate of ammonia/ 1 cwt., applied in late September. (6) Nitrate of soda, 149 lb., applied in late September. (7) Nitrate of soda, 149 lb., applied in late October. All plots received 1 cwt. per acre of super, applied with the seed. Six .experiments'of this type were sown. One of these, conducted on the farm of F. W. Carpenter, . Prebbleton, had a further treatment included in which the Imperial Chemical Industries product M.A.P.2, at 127 lb. per acre, was sown with the seed. The basal dressing of super, however, was omitted in this treatment. (Note. M.A.P.2 contains 18 per cent, of nitrogen and 18 per cent, of phosphoric acid.)

Trial of Superphosphate. — One experiment was sown on the farm of W. Edar, Sefton, in which super, at the rate of 1 cwt. and 2 cwt. per acre respectively, was compared with no manure.

Size of Plot and, Number of Replications. — As in the past few seasons, each plot was 2 chains in length and seven coulter rows wide. Twelve replications of each treatment were sown in most experiments, although ground available allowed only eleven to be sown in a few trials. In the experiments at Edar’s and Carpenter’s eighteen and twenty-four replications respectively were sown. In order to reduce the influence of possible “ fertility slope ” on yields, treatments were arranged in opposite order on each side of a middle plot.

Interpretation of Results. —A statistical examination of results was made in all experiments. Differences between treatments may be accepted with confidence when stated to be “ significant.” Those stated to be “ not significant ” cannot be accepted with any degree of confidence, though they may be real and in some cases quite appreciable.

Estimation of Profits or Losses from Manures applied. — No attempt has been made to assess the profits or losses resulting in the individual trials. General averages are used for estimating the monetary returns from fertilizers. The - prices used for determining the returns are as follows : Wheat, 4s. per bushel (per-bushel cost, such. as threshing, bags, hauling, railage, &c., are taken as about is., and this amount is deducted from the approximate price in round figures for Tuscan wheat delivered in store) ; superphosphate (ex store), 4s. per cwt. ; nitrate of soda, 17s. per cwt. ; sulphate : of ammonia, 11s. per cwt.

The amount of wheat required to meet the cost of 1 cwt. of each of the fertilizers used is approximately as follows : 1 bushel for 1 cwt. of super; 4{- bushels for 1 cwt. of nitrate of soda; 2f bushels for 1 cwt. of sulphate of ammonia. Particulars of Trials, Yields, and Differences between .. Treatments. Particulars of the individual trials, yields from the various treatments, and comparisons between treatments are set out in. Tables 1 to 7 which follow.

Trial of Superphosphate versus No Manure. — In Experiment 21, in which nitrogen plots were not included, the yields were as follows : No manure, 37-4 bushels; super, 1 cwt. per acre, 41-2 bushels ; super, 2 cwt., 41-9 bushels.

COMMENTS ON TABLES 4 AND 5. Sulphate of ammonia i cwt. (with seed). The average increase due to 1 cwt. sulphate of ammonia applied with the seed in the eighteen experiments shown in Table 4 was 0-9 bushels per acre. The relatively poor response from this treatment compared with sulphate of ammonia applied as. a top - dressing is probably due, in part at least, to its deleterious effect on germination.

./• Table .5 shows the average number of plants per 10-ft. length of row on each of the treatments no nitrogen and sulphate of . ammonia 1 cwt. (with seed) in those trials' on which counts were taken. In most of these trials counting was carried out twice —once soon after, the crop was through the ground, and again three or four weeks later. .

In eight trials the first counts . indicated that sulphate of ammonia had depressed germination, and in five of these on which second counts were taken there were still significant differences in favour of the no-nitrogen treatment, although they were reduced to some extent. The data indicate that the sulphate of ammonia both destroyed and delayed germination.

Apart from these trials, observations made on other experiments indicated that germination of sulphate of ammonia plots was reduced or delayed to a noticeable extent. In the case of Experiment 14, very severe germination injury resulting from sulphate of ammonia was reflected in a reduction in yield of 8-2 bushels below the no-nitrogen treatment.

Sulphate of ammonia 1 cwt. applied in August.— The average increase in yield due to the application of sulphate of ammonia 1 cwt. applied in August was 2-2 bushels per acre in the twenty experiments in which this treatment was included. Significant increases were obtained in eleven experiments, but only eight of them gave increases greater than the 2f bushels required to meet the cost of 1 cwt. of sulphate of ammonia. The average loss due to the use of 1 cwt. sulphate of ammonia amounts to 2s. 8d. per acre.

' '< COMMENTS ON TABLE 6. . - - Comparison of sulphate of ammonia i cwt. with nitrate of soda i cwt. In two experiments (Nos. 2 and 7) sulphate of ammonia 1 cwt. is significantly better than nitrate of soda 1 cwt. The average . difference in favour of sulphate of’ ammonia 1 cwt. is 0-45 bushels per acre, and if the paired yields are examined statistically this difference's just significant.

Comparison ■ of sulphate' of ammonia z| cwt. with nitrate of soda z| cwt. The average increase in favour of sulphate of ammonia when the larger quantities are compared is 0-78 bushels. . . £

In two trials significant increases were recorded in favour of the sulphate of ammonia. The .average difference in all trials is barely significant.

Comparison between sulphate of ammonia 1 cwt. and sulphate of ammonia z| cwt. —The use of the greater quantity of sulphate of ammonia has resulted in an average increase of o-86 bushels per acre over the . yields from the lesser amount, and in five experiments significant increases in favour of the greater quantity occurred. In Experiment 13 a significant depression in yield has been caused by the use of the larger quantity.

Comparison between nitrate of soda 1 cwt. and nitrate of soda z| cwt. The average increase from the greater over the lesser quantity of nitrate of soda is 0-54 bushels per acre, while in two experiments there are significant increases.

In Experiment 6 the greater quantity has caused a significant depression in yield, although in the same experiment r| cwt. of sulphate of ammonia was significantly, better than 1 cwt. It must be remembered, however, that whereas the sulphate of ammonia dressings were applied in August, nitrate of soda was applied in September, and the weather conditions prevailing at the time of top-dressing may have contributed to the apparently inconsistent results in this experiment.

Effect of nitrate of soda. — The average increase of 1 cwt. nitrate of soda over no nitrogen in the Type A experiments was 1-7 bushels per acre, which, taking the values previously mentioned, resulted in a net loss of 10s. 3d. per acre, while only in three experiments were increases obtained greater than 4| bushels, which was required to meet the cost of 1 cwt. nitrate of soda. COMMENTS ON TABLE 7. . The average yields shown in Table 7 indicate that greater effect per unit of nitrogen has been obtained from the use of nitrate , of soda, when applied in September and October, than with August or September‘dressings of sulphate of ammonia.

Sulphate of ammonia.— When late August and late September dressings of sulphate of ammonia are compared there is on the average very little difference between the yields. In thirteen trials conducted to date, and including the above, in which these treatments have been compared the average increase over no manure is 3 bushels per acre in each case.

Nitrate of soda. — October dressings of nitrate of soda have given slightly better results on the average than September dressings, although both September and October applications were superior , to August dressings. In only one experiment (No. 18), however, was the latter significantly below the September and October dressings in yield, although in. most of the trials there was a trend in favour of the later applications. Thirteen trials have been conducted to date in which August, September, and October dressings of nitrate of soda have been compared. The average increase over no nitrogen for each is 3-5, 4-4, and 4-6 bushels respectively. Effect of Superphosphate i cwt. In the three experiments in which super at 1 cwt. per acre plots could be compared with those receiving no manure, the increases due to super are as follows: Experiment No. 2, 7-6 bushels Experiment No. 6, 2-2 bushels; Experiment No. 21, 3-8 bushels. In . all cases these increases were, significant, and all profitable on the basis of 1 bushel being required to pay for the. fertilizer. Including the above, 13 experiments have been conducted over nine seasons in which super at 1 cwt. has been compared with no manure. The average increase due to 1 cwt. of super in these is 4-3 bushels. Summary and General Conclusions. The results of twenty-one manuring, trials on wheat conducted in the South Island in the season .1932-33 are given. With the exception of one trial, all experiments were designed to investigate the effect of nitrogenous fertilizers both with regard to quantity and time of application. The outstanding features are as follows : —

The sowing of 1 cwt. of sulphate of ammonia per acre with the seed resulted in germination injury or delayed germination of the seed in a large percentage of the trials, and this was in some cases followed by a detrimental effect on yield.

The average increase due to i cwt. sulphate of ammonia, applied with the seed, was 0-9 bushels per acre.

The average increases due to sulphate of ammonia i cwt. or nitrate of soda 1 cwt., applied to wheat as . a top-dressing, were 2-2 and 17 bushels per acre respectively. These increases would not be payable on the basis of the figures taken for price of wheat and cost of fertilizer nor were the further increases caused by using 11 cwt. of sulphate of ammonia or nitrate of soda respectively economical on the average.

Despite the favourable season for the wheat crop, the good results secured from nitrogen in the 1927-28 and 1928-29 seasons were not repeated in the 1932-33. season. While this. was equally true for the results of the two previous seasons, the conditions during the latter were unusually dry, and this fact was considered to some extent responsible for the poor results from the use of nitrogen. Such abnormal seasonal conditions did not obtain, however, during the 1932-33 season.

Late August to late September dressings have been in the main the best for sulphate of ammonia applications, while September and October dressings of nitrate of soda have generally proved better than those applied in August.

All experiments in which nitrogen-treated plots were compared received a basal dressing of super at 1 cwt. per acre with the seed. In the three trials in which plots receiving no super were included, the average increase due to the use of super 1 cwt. was 4-5 bushels per acre. In each case the increase was highly profitable.

The thanks of the Department are extended to those farmers who. provided land and facilities for carrying out the foregoing experiments.. .'■■■• ■ ’ • ' • The field work in connection with the experiments was carried out under the direction of Mr. R. McGillivray, Fields Superintendent, Christchurch, by Instructors G. G. Calder, Christchurch, E. M. Bates, Ashburton, W. Stafford, Timaru ; and under the .direction of Mr. R. B. Tennent, Fields Superintendent, Dunedin, by Instructor T. A. Sellwood, Oamaru. —A. W. Hudson, Crop Experimentalist, Plant Research Station. — W. Woodcock, Assistant Crop Experimentalist.

Grass Grub in Strawberry Beds. Mr. R. E. Binfield, Fruit Inspector, Nelson, reports : " During investigations made in the Nelson district • one instance came under notice at Stoke where on an area which had been left uncultivated and had prolific weed growth the strawberry plants did not suffer so severely from the attack of the grub as did the plants in adjacent beds which had been kept cultivated, but the weed and grass roots suffered considerably. The grub, however, seems to feed on any living roots in the vicinity, and infections appear heavier where grassland is turned over to the growing of strawberries, &c., without having first had at least two cleaning crops such as potatoes.”

date date was in represent to applied. were

* See Table 1 for location of trials. t Treatment not included in these trials. No-manure plots were sown in these cases, the yield in Experiment 2 being 32-6 bushels per acre and in Experiment 6 the yield of no manure was 47-6. f Severe germination injury.

•See Table 1 for location of trials. fin Experiment 17 the yield of M.A.P.2 at 127 lb. per acre (sown with seed) was 57-5 bushels. This treatment gave a significant increase over no nitrogen of 6-4 bushels per acre.

* This treatment not included in trial. Note.—Figures in heavy type in this and subsequent tables, where such occur, represent statistically significant differences.

* Increases.

Note.—Figures preceded by a minus sign denote a decrease.

Serial No., Name. Address. History ' ?■. ■; ■ ■ . . Wheat. Variety Rate of Seeding per Acre. Date sown. • . Date Nitrogen top-dressed. Date harvested. Variety of Wheat. Rate of Seeding per Acre. Date sown. ; Date Nitrogen top-dressed. Date har- ; vested. Type lb. I Burt . Hawarden.. feed; wheat Tuscan 104 25/5/32 V 2.4/8/32*\ / 25/1/33 ■ 2 J. Culverden wheat; Solid-straw 102 25/5/32 J 25/8/32 t f 24/1/33 3 Smith 0. Rangiora old previously Solid-straw 121*2 21/5/32 J x f 3/2/33 4 Mulholland Darfield ; Tuscan 98 18/5/32 23/8/32 \ 23/9/32 / 26/1/33 f 23/8/32 \ 23/9/32 f 26/1/33 5 T. Hororata .. I ; Solid-straw 102 17/5/32 \ 24/8/32 f 2/2/33 6 R. McMillan Irwell ; .. Hunter’s 85 29/5/32 \ 23/8/32 f ’23/1/33 7 J. Meth .. turnips; wheat Solid-straw 99 14/6/32 25/8/32 X 28/9/32 f "Y 25/8/32 \ 28/9/32 / 7/2/33 8 S. Lyndhurst wheat oats rape; Tuscan 88 11/6/32 r 25/8/32 \ 21/9/32 r 27/1/33 j 25/8/32 \ 21/9/32 f 27/i/33 9 J. . Winchmore Italian wheat -3 . , Solid-straw 89 8/6/32 18/8/32 \ 21/9/32 f 17/2/33 { 18/8/32 4 21/9/32 J 17/2/33 -io A. . Wakanui wheat 1928-29, peas Tuscan ; 90 1/6/32 ‘18/8/32 \ 19/9/32 f . 30/1/33 { 18/8/32 4 19/9/32 f 30/1/33 II W. McCully Temuka fallowed ; Hunter’s 100 26/5/32 { \ 23/8/32 J 8/2/33 12 High Timaru ; Solid-straw 124 7/7/32 ■ \ 28/8/32 J 10/2/33 13 C. Lyalldale grass Solid-straw 121 .14/7/32 \ 27/8/32 f .13/2/33 x • R. Pukeuri 1927-32, . Dreadnought 120 31/5/32 \ 25/8/32 f 3/2/33

Table 1.-Particulars of Individual Trials.

15 G. Cross Oxford .. ; 1930-31, Solid-straw 95 12/7/32 C and (3 7/2/33 1 j } and I ; r (3 j 7/2/33 !> i6 High School.. Rangiora potatoes; 1925-30, grass Tuscan 116 13/6/32 i (5 and 28/9/32 1 (7) 30/1/33 1 (7) I 27/10/32 _ f (3 and 4) 22/8/32 30/1/33 • - I 27/10/32 ■; r (3 and 4) I 22/8/32 17 F. W. Prebbleton . potatoes; grass Tuscan 108 . 29/5/32 I (5 21/9/32 I (7) 1/2/33 L • (3 f 24/8/32 1/2/33 18 Spence . . Sherwood oats; Tuscan 89 27/5/32 (5 J 17/1/33 j (7) ■ 17/1/33 20/10/32 J 1 (7) (3 and f [_ 20/10/32 23/8/32 r (3 and 4) 23/8/32 19 A. B. Hilton 1927-31, rape; grass Tuscan 100 9/6/32 J and > 6/2/33 28/9/32 ). 6/2/33 l/n/32 _ (7) J (3 and ( (3 f ? 1 - 6/9/32 20 J. Ngapara years’ Solid-straw 106 27/5/32 (5 > 17/2/33 1 ’ 21/9/32 > 17/2/33 1 (7) L 27/10/32 . ■ • ■■ Trial No 1 (7) L 27/10/32 21 W. Sefton .. potatoes; Hunter’s 104 27/5/32 1 2/1/33 potatoes .1 Hunter’s 104 27/5/32 1 1 2/1/33

Type B Experiments.

Serial No.* No Nitrogen. Sulphate of Ammonia, . 1 cwt., with Seed. Sulphate of Ammonia, 1 cwt., topdressed; ' Sulphate of Ammonia, 11 cwt., topdressed. Nitrate of Soda, 1 cwt., top-dressed. Nitrate of Soda, 1} cwt., top-dressed. - I . 31-1 34 : 8 36-4 35'8 35’8 35'9 2 . . 40-2 . t 40-8 44-6 39'7 41 • 3 .47-2 48-2 48 • 2 49’4 47’9 48-8 . . 4 34'3 32-2 . 34-8 35-i 34-3 33-6 5 44'9 44’2 46-6 47'3 46-0 46-4 6 49-8 . ' t 48-6 " 50-1 49-2 47'2 7 55'9 56-3 56-6 55’7 55’3 55-9 8 46 • 6 48-5 ■ 47'5 47-6 47-1 47'8 9 32-5 34 -8 35-7 37'2 35'3 37’3 IO 60 • 0 61 -2 62 ■ 63-7 61-5 61 • ii • .. 45-i 48-5 50-1 52'2 48-9 50-7 12 . 28- 1 31-0 32-4 32-6 32-2 33'8 13 42 • 1 . 42 • I 44’2 41 • 8 43’1 43-o 14 34’5 26 -3t 38-5 41-6 40 • 0 4°’5

Table 2. —Yields in Bushels per . Acre from Different Treatments in Type A Experiments. (All treatments received 1 cwt. super per acre in addition to the fertilizers stated.)

I. 2. 56. 7. ■ »-' I. 2. 3. 4- ' 56. 7. Serial No.* Sulphate of Sulphate of No Ammonia, 1 cwt. Nitrogen. (applied Sulphate of Ammonia, 1 cwt., with seed. Sulphate of Ammonia, 1 cwt. (applied August). ■ Nitrate Sulphate of Nitrate Nitrate No of Soda, Ammonia, of Soda, Ammonia, of Soda, of Soda, Nitrogen. 149 lb. 1 cwt., with seed. . (August). Sulphate of Ammonia, 149 lb. 1 cwt. (August). (September). Nitrate of Soda, 1 cwt. 1491b. (September). (September). Nitrate of Soda, 149 lb. 149 lb. (September). (October). 149 lb. (October). 15 • • 31-9 27-4 32-0 32-7 31-3 32'3. 33'1 16 34’7 43-1 . 38-9 40-5 40-7 • 44'2 43’1 i7t .. 5I: 1 55’3 56-8 55-o . 56-5 55'2 56-9 18 ... 39’9 4i-3 42-9 42-3 43’2 43'8 43’9 19 . . 27-3 2829'3 29’3 30’5 30-2 29-0 20 40-6 40-0 40-4 40-2 39-5 40-2 ■4I-5

Table 3. —Yields in Bushels per Acre in Type B Experiments. (All treatments received 1 cwt. super in addition to the fertilizers stated.)

Serial Increase due to Manures. Serial No. No. Increase due to Manures. Increase due to Manures. Increase of Sul-Serial phate of Ammonia.' No. Increase due to Manures. Increase of Sulphate of Ammonia r cwt. (with seed) over No Nitrogen. Increase of Sul- , phate of Ammonia i cwt. - (August), over No. Nitrogen. Increase of Sulphate of Ammonia 1 cwt. (with seed) over No Nitrogen. Increase of Sulphate of Ammonia . 1 cwt. (August),' over No Nitrogen. No. I . . 3-7 5-3 II . . 3-4 50 2 . . * o-6 12 2-9 4-3 3 • • I • o I o 13 • • o-o . 21 4 • • -21 ? ■ o-5 14 .. — 8-2 40 5 •• -0-7 i-7 15 • • — 4-5 o-1 6 . . ❖ ■ ■- 1-2 16 . . 8-4 4-2 7 • • o-4 o-7 17 .. 4-2 - 5-7 8 .. 1-9 o-9 18 .. 1-4 , 30 9 • • 2-3 3-2 19 . . o-8 20 IO I -2 2-2 20 . . — 0-6 — 0-2 ' ■* Average increases—18 trials . . 0-9 20 trials 2-2

Table 4.Differences in Yields in Bushels -per Acre (a) Between No Nitrogen and Sulphate of Ammonia 1 cwt., applied with seed, and (b) Between No Nitrogen and Sulphate of Ammonia 1 cwt., applied in. August. (Type A and B Experiments.)

Experiment Serial No. Average Number of Plants per io ft. Length of 1 Coulter Row (Middle Coulter). First Count. ; . Second Count. No Nitrogen. Sulphate of Ammonia, 1 cwt. (with seed). Percentage Reduction. No Nitrogen. Sulphate of Ammonia, 1 cwt. (with seed). Percentage Reduction. 7 76-3 68-8 9-8 Not taken. 8 92 • I ■82 10-4 84 • 79-9 51 9 . • • 94 -2 86-4 ■ 8-3 101 -8 95-5 6-2 IO ■ 84 • . 75‘4 . 10-3 Not taken. 15 65-1 60 • 0 7-8 68-3 66-i 3-2 16 59-8 . 59’2. 1-0 62-5 64-6 3‘4* 17 94'7 66-4 29-9 - 98-6 ' . 83-7 151 18 86-6 71-3 17-7 91-8 77’4 15-7 19 • • 49-8 49’3 1 • o Not taken. 20 . . 69-5 65-3 6-o 1 80 ■ 7 87-5 8-4*

Table 5. —Plant Counts on Treatments No Nitrogen and' Sulphate of Ammonia I cwt. (with Seed) taken from several Experiments.

Experiment (a) (*) Sulphate of Ammonia i cwt. Serial No. (August) : Increase (a) (b) Sulphate of Ammonia 1 cwt. (August) : Increase or Decrease in relation to Nitrate of ' Soda i cwt. ■ (September). Sulphate of Ammonia i-J cwt.: Increase or Decrease . in relation to Nitrate of Soda . i| cwt. . . Sulphate of Ammonia r| cwt. : Increase or Decrease in relation to Sulphate of Ammonia 1 cwt.. (August). Nitrate of Soda ij cwt..: Increase or Decrease in relation to Nitrate of Soda 1 cwt. Serial No. I . . o • 6 — O • I -0-6 O- I 2 ... 11 3-4 3-8 1-5 3 o-3 o • 6 ■' i-2 ■ A’ o-9 4 ' ' ••• o-5 1’5 o-3 -0-7 5 o-6 * 0-9 0-7 0-4 6 — o-6 2-9 1-5 -20 7 1-3 — 0*2 v- — o-9 o-6 8 . .. 0-4 - — 0-2 ‘ , 0 • 1 • . 0-7 9 • • 0-4 — o • I , „ 1-5 20 IO ... o-7 2-0 i-5 0 • 2 ii - . . 1-2 . _ i-5 . 2 • 1 .. i-8 12 . . 0'2 ' — 1-2 0 ■ 2 -6 13 I • I — I 2 . 2-4 — o-1 14 . .. -i-5 I • I 31 • °-5 , Av e r a g e o-45 o-86 . . o-54 increase 0’45 0-78 0 • 86 °’54

Table 6. (a) Comparison .of Sulphate of Ammonia with Nitrate of Soda at I cwt. and cwt. per Acre respectively ; (b) Effect of increasing Sulphate of Ammonia and Nitrate of Soda respectively from i cwt. to cwt. per Acre. (Type A Experiments.)

Serial No.. Differences of Nitrogen Treatments from No Nitrogen, in Bushels per Acre. ' ■ ■ ' ■ . .. ' . August Dressings. September Dressings. October Dressings.. Dressings. ' October Dressings. Sulphate of Ammonia, r cwt. Nitrate of Soda, 149 lb. Sulphate of Ammonia, 1 cwt. Nitrate of Soda, 149 lb. Nitrate of Soda, 149 lb. 15 ‘ • • O-I 0-8 — 0-6 0-4 I *2 16 4-2 5-8 60 9-5 8-4 17 5-7 3-9 5-4 41 5-8 18 30 2-4 • 3-3 3-9 40 IQ 20 20 3-2 2-9 i-7 20 . . -0-2 -o-4 — 1 • 1 -o-4 o-9 ■ -o-4 0-9 Average in2’5 2 • 4 2’7 3'4 3'7 crease 2‘5 ■ 2-4 . 2-7 . 3'4 3’7

Table 7. —Showing Effect of August and September Dressings of Sulphate of Ammonia, and August, September, and October Dressings of Nitrate of Soda (equivalent Quantities of Nitrogen).