AUTUMN AND WINTER APPLICATION OF NITROGEN FERTILIZERS ON CLAY SOILS Yrjö Pessi, Mikko Ylänen, Auvo Leskelä and Jorma Syvälahti Rikkihappo Oy, Helsinki Received July 7, 1970 Abstract. In order to examine the application time of nitrogen given to cereals, several tests have been arranged on the Kotkaniemi Experimental Farm at Vihti ever since 1965. The tests have been carried out on solid clay soils, where the leaching of nitrogen has been expected to be slow. In spring cereals the autumn application of nitrogen in November on frozen soil has given a good crop yield. The protein content of the crop in the plots where nitrogen was given in autumn was lower than in those where the spreading took place in spring. As for winter wheat, application in December has given the best average crop yields but the decline of the protein content is to be considered a disadvantage. In rye, spring fertilization has given the best average crop yield. There has, however, clearly been less lodging in autumn applications than in plots where the nitrogen was spread in the spring. Regarding nitrogen fertilization of autumn sown plants the usual custom in Finland is to give nitrogen in autumn for growth during the autumn and in the spring for the coming growing season. However, as low rainfall is typical of the Finnish spring, the effect of nitrogen given by broadcasting in early summer is slow, especially on solid soils like clay. As for spring cereals, the fertilizer placement at a depth of 8 to 10 cms has given distinctly better results than broadcasting and the usual mixing into the soil (Elonen 1967, Larpes 1966 and 1968, Nieminen 1967, Pessi 1970). The difference in the growth intensity has most clearly been evident in the early development of cereals. Simultaneously it has become clear that the placement of nitrogen has been of the greatest importance (Pessi 1970). As during winter in Finland the soil is usually frozen and covered with snow, no noteworthy leaching of nutrients takes place. On the basis of the results and observations mentioned above the question are as to what it would mean in practice in solid soils if the nitrogen was spread already before snowfall or on the snow, when the water from the melting snow would in spring cause the nitrogen to penetrate the soil. For this purpose tests were started on the Kotkaniemi Experimental Farm of Rikkihappo Oy in autumn 1965. Arrangement of test The tests were carried out on silty sandy clay through which water penetrates slowly. The physical character of the soil appears in the following analysis: clay, diameter less than 0,002 mm, 42 %; diameter 0.002—0,2 mm, 33 %; diameter over 0.02 mm, 25 %. In the arrangement of the tests a test plot of such dimensions was planned, even several ares, that the work could be done by farming machines in all its phases while the test plots simultaneously gave a clear picture of the growth form of the crops. There were usually 4 replications. In large test plots the unhomogeneity of the soil causes more dis- https://www.c-info.fi/en/info/?token=Gd44TnUCUSlh7Ifs.vs1YssBScoDbRIfguYxFHA.9HP4KuUkPNSqFsvpTGgG3P0Xa4qU002TUSfd2OfsiOySfyq1XjGnIjDYoFwsB6Bq4tUE9vXI0lPiz3J9iDr7TL9sv1WGjSLNymG5Ge2KGu-aydrGMvvy1Q5j-NexZVvwSUUIK5C0xba9jutx5VGpu78_tPeSI6NbvLTtUC-RQ4gr0VZ-ShBvjb-pjwJF_H4LXz7Q_XiSJUaWFE4 77 persion than in small ones; also the area needed by the test plot is large, positive points on the fact that it is possible to use ordinary farm-working techniques and to adapt the results directly into practice. The meteorological conditions are shown in Table 1 Table 1. Meteorological Observations at Vihti during the Growing Seasons 1965—69. Monthly precipitations in millimetres V VI VII VIII IX Total 1965 8.3 18.1 106.9 90.0 65.0 288.3 1966 15.1 40.7 74.9 28.3 77.7 236.7 1967 51.9 21.8 27.8 142.1 53.3 296.9 1968 70.5 30.6 67.1 111.4 74.4 354.0 1969 21.6 15.5 45.3 40.1 95.9 218.4 Average 33.5 25.3 64.4 82.4 73.3 278.8 Average temperatures per monthly in °C Average V VI VII VIII IX (V—IX) 1965 7.7 16.0 14.6 13.4 11.6 12.66 1966 9.4 17.9 17.9 13.8 7.9 13.38 1967 10.1 14.7 17.6 15.2 10.5 13.62 1968 7.4 16.2 14.5 15.3 10.0 12.68 1969 8.7 15.3 16.2 15.2 9.6 13.00 Average 8.7 16.0 16.2 14.6 9.9 Results Spring cereals. The tests were started by using spring cereal as an experi- mental plant in fertilizations in autumn 1965. In 1966 they were expanded to include also winter cereals. The results of the experiments with compound fertilizer (8-13-9, N-P205-K 20) are given in Table 2. Nitrogen given in autumn has in the tests given a clear increase in the crop yield, but spring fertilization has proved even better. However, it is to be noted that the superiority of spring fertilization in this case cannot with certainty be attributed to the better effect of nitrogen. It is well known that water-soluble phosphorus, which the used compound fertilizer contains, fixes fairly fast in a less soluble form. In autumn application this has happened more than in the spring application. The three quality factors of the crop yield in Table 2 have not been affected by the time of fertilization. There has been no noteworthy lodging in any treatment. Tables 3 and 4 present the 4-year results of the tests carried out with four different nitrogen fertilizers. They show that different fertilizers have given very similar results. Autumn application in November has usually given the best results, ammonium sulphate alone has proved an exception, in a way against all expectations. In the quality of the crop yield a clear consistency is to be seen in the protein contents of the cereals. In connection with autumn applications it is lower than in spring applications. Table 3. Tests with spring cereals during application time of nitrogen in 1965 —1969. 1965 — 66 Soil type sandy muddy clay. Nutrient in 1962 pH 5.6, Ca 2080, P 3.5, K 180. Tests made with Svenno wheat. Sown 17. 5. Harvested 12.9. Size of test plot 10 X 10 m. Quantity of nitrogen used 150 kg N/ha. Fertilization in autumn 1 000 kg/ha of PK fertilizer (0-17-15). 1966 — 67 2nd test year.Soil type sandy silty clay. Nutrients in 1967 pH 5.9, Ca 2 900, P 4.2 and K 170 mg/1. Test made with Svenno whaet. Sown 17.5. Harvested 5.9. Size of test plot 10 X 10 m. Quantity of nitrogen used 150 kg N/ha. Fertilization in autumn 1 000 kg/ha of PK fertilizer (0-17-15). 1967 — 68 3rd test year. Soil type sandy clay. Nutrients in 1967 pH 5.2, Ca 2 200, P 3.3 and K 280 mg/1. Tests made with Balder barley. Sown 1.6. Harvested 11.9. Size of test plot 10 X 20 m. Quantity of nitrogen used 150 kg N/ha. Fertilization in autumn 1 000 kg/ha of PK fertilizer (6-17-15). 1968 — 69 4th test year. Soil type silty sandy clay. Nutrients in 1967 pH 5.8, Ca 2 525, P 5.3 and K 335 mg/1. Tests made with Porno barley. Sown 8. 5. Harvested 13. 8. Size of test plot 10 x 30 m. Quantity of nitrogen used 150 kg N/ha. Fertilization in autumn 1 000 kg/ha of PK fertilizer (0-17-15). 1966 1967 1968 1969 Averages Treatment Grain yield Grain yield Grain yield Grain yield Grain yield kg/ha rel. kg/ha rel. kg/ha rel. kg/ha rel. kg/ha rel. I By different fertilizers 1. Without nitrogen 2 390 100 2 740 100 2 190 100 1 100 100 2 110 100 2. Calcium nitrate early October 3 370 141 3 570 130 3 760 172 2 740 249 3 360 159 3. » » in November 3 380 141 4 060 148 4 000 183 3 900 354 3 840 182 4. » » in December 2 990 125 4 250 155 3 640 166 2 310 2io 3 300 156 100 5. » » in spring after melting of snow 3 350 140 4 070 149 3 060 140 2 380 216 3 220 153 6. » » in spring at normal fert. time 3 150 132 4 300 157 3 180 145 2 620 238 3 310 157 7. Calcium ammonium nitrate early October 3 710 155 3 870 141 2 600 119 1 070 97 2 810 133 8. » » » in November 3 520 147 4 650 170 3 400 155 2 520 229 3 520 167 9. » » » in December 3 240 135 4 170 152 3 720 170 1 880 170 3 260 155 93 10. » » » in spring after melt, snow 3 500 147 4 270 156 3 370 154 1 850 168 3 250 154 11. » » » » at norm.fert. time 3 180 133 4 190 153 3 500 160 1 380 125 3 060 145 78 1966 1967 1968 1969 Average Treatment Grain yield Grain yield Grain yield Grain yield Grain yield kg/ha rel. kg/ha rel. kg/ha rel. kg/ha rel. kg/ha rel. 12. Ammonium sulphate nitrate early October 3 260 136 3 930 144 2 900 132 2 460 223 3 140 149 13. » » » in November 3 270 137 4 530 166 2 070 94 2 770 252 3 160 150 14. » » » in December 2 860 119 3 620 132 2 280 104 3 070 279 2 960 140 90 15. » » » in spring after melt, snow 3 210 134 4 010 147 1 610 73 3 290 299 3 030 144 16. » » » » at norm.fert. time 3 300 137 4 010 147 1 870 86 3 100 282 3 070 145 17. Ammonium sulphate early October 3 530 147 3 900 143 3 240 148 3 620 329 3 570 169 18. » » in November 3 140 131 4 580 167 2 900 133 2 630 239 3 310 157 19. » » in December 2 950 123 4 010 147 2 590 118 1 590 144 2 790 132 99 20. » » in spring after melt, snow 3 310 138 4 010 147 3 070 140 2 620 238 3 250 154 21. » » » in spring at norm.fert. time 3 640 152 4 200 153 3 320 152 4 580 417 3 940 187 II By application periods ( averages) 1. Without fertilizing with nitrogen 2 390 100 2 740 100 2 190 100 1 100 100 2 110 100 2. Nitrogenous fertilization early October 3 470 145 3 820 140 3 130 143 2 470 225 3 220 153 (100) 3. » » in November 3 330 139 4 460 163 3 090 141 2 950 268 3 460 164 (107) 4. » » in December 3 010 126 4 010 147 3 060 140 2 210 201 3 070 145 ( 95) 5. » » in spring afr. melt, snow 3 340 140 4 090 149 2 780 127 2 540 230 3 190 151 ( 99) 6. » » » at norm.fert. time 3 310 138 4 170 153 2 970 136 2 920 265 3 340 158 (104) In 1966 In 1967 In 1968 In 1968 Averages of years Grain yields, application times F = 4.63* F = 5.35* F = 0.40 F = 3.50* F = 0.41 saltp. grades F = 2.29 F = 1.10 F = 9.51 F = 3.34* F = 0.49 sx = 2.4 % sx = 10.1 % sx = 7.4 % sx = 15.35 % = 14.81 % Different In spring 1968 there werewaters of melting snowon the area spread with ammonium suplhate nitrate which mayhave years contributed to the weak effect. In 1969, the area spread with calcium ammonium nitrate wasas an area dryer than the others. F = 7.53** 79 Table 2. Average values of results from tests with spring cereals during application time of fertilizers (compound fertilizer 8-13-9) in 1965—69. 1965—66 Soil type sandy muddy clay. Nutrients in 1962 pH 5,6, Ca 2080, P 3.5, K 180. Test made with Svenno spring wheat. Size of test plot 10 m X 50 m. 3 replications. Fertilization: 800 kg/ha of compound fertilizer 8-13-9. 1966—67 Soil type silty clay. Nutrients in 1967 pH 5,9, Ca 2 900, P 4.2 and K 170 mg/1. Test made with Svenno wheat. Size of test plot 10 m X 50 m. 3 replications. Fertilization: 800 kg/ha of compound fertilizer 8-13-9. 196768 Soil type clayey humus soil. Nutrients in 1967 pH 5.2, Ca 2 475, P 4.4 and K 300 mg/1. Test made with Balder barley. Size of test plot 10 m X 50 m. 4 replications Fertilization: 800 kg/ha of com- pound fertilizer 8-13-9. 196869 Soil type silty sandy clay. Nutrients in 1967 pH 5.8, Ca 2 390, P 5.7 and K 364 mg/1. Test made with Porno barley. Sown 8.5. Harvested 12. 8. Size of test plot 10 m X 50 m. 4 replications. Fertiliza- tion: 800 kg/ha of compound fertilizer 8-13-9. Grain yield Treatment (4 test) Lodging HI- 1000 g.w. Raw kg/ha rel. % weight g protein % 1. Without fertilization (test results only from 1966—67) 2. PK fertilization on ploughed area early October 3. 8-13-9 fertilization before ploughing » » 4. » » after ploughing » » 5. » » on ploughed area after mid- dle of November 6. 8-13-9 fertilization on ploughed in spring after melting of snow 7. 8-13-9 fertilization on ploughed in spring at normal fertilizing time Grain yields In 1966 In 1967 1 820 100 0 81.7 35.0 1 890 104 1 75.2 37.6 9.7 2 500 137 1 76.1 37.9 10.0 2 560 141 0 75.4 39.5 9.5 2 650 146 5 76.1 39.6 9.2 3 080 169 9 74.9 40.1 10.2 2 880 158 0 75.0 38.7 10.0 In 1968 In 1969 F = 16.35*** F = 7.54** F = 4.54* F = 2.66 sx = 3.11 % sx = 9.06% sx = 6.70% s* = 12.54% Winter cereals. The results of the tests carried out with winter cereals are presented in Tables 5 to 8. Tables 5 and 6 show the results of winter rye and Tables 7 and 8 those of winter wheat. No treatment without nitrogen fertilization was included in the tests but on the basis of other tests made in the same area it is possible to conclude that the crop yield without nitrogen fertilization is for rye 2140 kg/hectare and for winter wheat 2270 kg/hectare. The results show that for rye spring fertilization has given the best results on an average, and for winter wheat spreading in December. Yearly fluctuations have apparently existed, at least partly, because of the rain frequency of the spring. There have been clear differences in lodging. The smaller lodging of rye in connection with autumn applications compared with spring applications would seem to recommend autumn application of nitrogen on clay soils in connection with intensive cultivation aiming at high crop yield. On the other hand, the decline of the protein content of winter wheat in connection with autumn application ofnitrogen is a disadvantage for thebaking quality of the crop. 80 Table 4. Average values of results from tests with spring cereals during application time of nitrogen in 1966 —1969. Tests made with Svenno wheat in 1966 —67, Balder barley in 1968, Porno barley in 1969. Grain yield (4 tests) Raw Treatment Lodging Hl-weight 1 000 g.w. protein % kg/ha rel. rel. by % 8 (only in 1969) fert. grades I By different fertilizers 1. Without nitrogen 2 110 100 0 78.2 38.4 8.6 2. Calcium nitrate, early Oct. (ground not frozen) 3 360 159 11 78.0 38.6 10.7 3. » » November (ground frozen) 3 840 182 14 75.6 39.3 8.7 4. » » December (ab. 20 cm snow) 3 300 156 100 14 79.2 39.4 10.1 5. » » April (in spring after melt, snow) 3 220 153 3 77.9 39.5 12.9 6. » » May (in spring at norm.fert. time) 3 310 157 5 77.6 39.6 13.2 7. Calcium ammonium nitrate, early October 2 810 133 1 78.2 38.4 10.1 8. » » » November 3 520 167 79 39.4 39.4 11.8 9. » » » December 3 260 155 93 3 78.3 38.1 11.4 10. » » » April 3 250 154 2 77.3 38.7 10.7 11. » » » May 3 060 145 6 77.8 38.9 12.5 12. Ammonium sulphate nitrate, early Oktober 3 140 149 2 80.0 39.1 10.6 13. » » » November 3 160 150 2 78.8 40.0 11.7 14. » » » December 2 960 140 90 0 78.5 40.1 12.7 15. » » » April 3 030 144 1 78.0 40.0 12.4 16. » » » May 3 070 145 1 78.4 40.5 13.0 17. Ammonium sulphate, early October 3 570 169 4 79.1 39.9 10.0 18. » » » November 3 310 157 2 78.9 40.3 10.3 19. » » » December 2 790 132 99 1 78.3 38.9 11.3 20. » » » April 3 250 154 1 77.8 40.3 12.6 21. » » » May 3 940 187 2 78.4 40.6 12.4 Grain yields, treatments2— 21: fertilizer grades F = 0.49 application periods F = 0.41 years F = 7.53** (= various plants also) sx = 14.81 % II By application periods 1. Without nitrogen 2 110 100 0.25 76.0 38.4 9.8 2. Early October (ground not frozen) 3 220 153 (100) 4.75 76.0 39.9 11.1 3. November (ground frozen) 3 460 164 (107) 5.5 u 76.1 39.6 11.7 4. December (ab. 20 cm snow) 3 070 145 ( 95) 4.75 75.8 39.2 12.4 5. April (in spring after melt, of snow) 3 190 151 ( 99) 2.25 75.1 39.5 12.9 6. May (in spring at normal fert. time) 3 340 158 (104) 3.75 75.0 39.4 13.4 Grain yields, treatments I— 6: fertilizer periods F = 18.87*** years F = 47.56*** (in 1968 — 69 barley) without/N fert. F = 87.52*** sx = 3.66 % Grain yields, treatments2—6: fertilizer periods F = 2.29 years F = 52.23*** (in 1968 — 69 barley) s, = 3.00 % 81 82 Table 5. Test with winter rye during nitrogen application time. 1966—67 Soil type silty sandy clay. Nutrients in 1967 pH 5.8, Ca 2 500, P 5.3 and K 335 mg/1. Fertiliza- tion in connection with seed-bed preparation 500 kg compound fertilizer (8-13-9) and 600 kg/ha PK fertilizer (0-17-15) by broadcasting. Tests made with Pekka rye. Size of test plot 5 m X 50 m. 4 replications. For shoots 150 kg N/ha as calcium ammonium nitrate. 1967—68 Soil type silty clay. Nutrients in 1967 pH 5.8, Ca 2 600, P 6.4 and K 220 mg/1. Fertilization in connection with seed-bed preparation 600 kg compound fertilizer (8-13-9) and 500 kg/ha PK fertilizer by drilling. Tests made with Pekka rye. Size of test plot 10 m x 20 m. 4 replications. For shoots 150 kg N/ha as calcium ammonium nitrate. 1968—69 Soil type clayey sand and silt. Nutrients in 1967 pH 5.8, Ca 2 100, P 10 and K 315 mg/1. Fer- tilization in connection with seed-bed preparation 700 kg/ha compound fertilizer (15-25-10) by drilling. Tests made with Pekka rye. Size of test plot 7 m X 27 m. 3 replications. For shoots 150 kg N/ha as calcium ammonium nitrate. 1967 1968 1969 Averages Nitrogen application time Grain yield Grain yield Grain yield kg/ha rel. kg/ha rel. kg/ha rel. kg/ha rel. 1. Early October 3 540 100 1 920 100 3 740 100 3 070 100 1 870 98 3 410 91 3 110 101 1 800 93 3 370 90 3 080 100 1 860 97 3 180 102 3 250 106 2 340 122 3 740 100 3 350 109 2 430 127 3 980 106 3 460 113 2. » November 4 040 114 3. » December 4 070 115 4. 20—40 cm snow 4 070 115 5. In spring after melting of snow 3 960 112 6. At normal spreading time 3 980 1123 980 112 1967 1968 1969 F = 3.95* F = 1.06Grain yields F = 1.15 Sx =4.74 % 6.70 % =6.27 % Table 6. Test with winter rye during nitrogen application time. 1966—67 Soil type silty sandy clay. Nutrients in 1967 pH 5.8, Ca 2 500, P 5.3 and K 335 mg/1. Ferti- lization in autumn 1966 with 500 kg compound fertilizer (8-13-9) and with 600 kg/ha PK fertilizer (0- 17-15) by broadcasting. Tests made with Pekka rye. Size of test plot 5 m X 50 m. 4 replications. Ferti- lizing with 150 kg N/ha as calcium ammonium nitrate. 1967—68 Soil type silty clay. Nutrients in 1967 pH 5.8, Ca 2 600, P 6.4 and K 220 mg/1. Fertilization in connection with seed-bed preparation: 600 kg compound fertilizer (8-13-9) and 500 kg PK fertilizer/ha by drilling. 150 N/ha as calcium ammonium nitrate given for shoots. Tests made with Pekka rye. Size of test plot 10 m X 20 m. 4 replications. 1968—69 Soil type clayey sand and silt. Nutrients in 1967 pH 5.8, Ca 2 100, P 10 and K 315 mg/1. Ferti- lization in connection with seed-bed preparation with 700 kg/ha compound fertilizer (15-25-10) by drilling. For shoots 150 N/ha as calcium ammonium nitrate. Tests made with Pekka rye. Size of test plot 7 m X 27 m. 3 replications. 83 Over- Grain yield wintering 1 000 Raw Treatment Lodging observ. HI- g.w. Falling protein % 13. 4. 67. weight g number %*) x kg/ha rel. covering % 1. Early October 3 070 100 36.8 92.8 75.9 26.6 190 9.6 2. » November 3 110 101 38.3 89.0 76.1 28.5 207 9.8 3. » December 3 080 100 41.0 88.4 76.4 26.0 196 11.2 4. 40 cm snow 3 250 106 41.2 90.3 76.6 25.8 192 10.1 5. In spring after melting of snow 3 350 109 77.7 89.5 75.9 26.5 191 12.4 6. At normal fertilizing time 3 460 113 82.8 89.4 75.7 26.3 189 10.6 Grain yields, F-value = 0.15 (different years F = 12.27**) *) Only in 1969. Table 7. Test with winter wheat during nitrogen application time. 1966—67 Soil type silty sandy clay. Nutrients in 1967 pH 5.9, Ca 3 100, P 8.8 and K 170 mg/1. Fertili- zation in connection with seed-bed preparation with 1 000 kg/ha PK fertilizer (0-17-15) by broadcasting. Tests made with Linna wheat. Sown 3. 9. 66. Harvested 23. 8. Size of test plot 5 m X 50 m. 4 replications. For shoots 150 kg N/ha as calcium ammonium nitrate. 1967—68 Soil type silty clay. Nutrients in 1967 pH 5.5, Ca 3 375, P 4.0 and K 290 mg/1. Fertilization in connection with seed-bed preparation: 600 kg compound fertilizer (8-13-9) and 500 kg PK fertilizer/ha by drilling. Test made with Linna wheat. Sown 7. 9. 67. Harvested 22. 8. 68. Size of test plot 8 m x 30 m. 4 replications. For shoots 150 kg N/ha as calcium ammonium nitrate. 1968—69 Soil type clayey sand and silt. Nutrients in 1967 pH 5.8, Ca 2 025, P 4.8 and K 284 mg/1. Fartilization in connection with seed-bed preparation with 700 kg/ha compound fertilizer (15-25-10) by drilling. Tests made with Linna wheat. Sown 5. 9. 68. Harvested 12. 8. 69. Size of test plot 10 m X 50 m. 4 replications. For shoots 150 kg N/ha as calcium ammonium nitrate. (When coming into ear another 200 kg/ha calcium ammonium nitrate was given). 1967 1968 1969 Averages of Nitrogen application time Grain yield Grain yield Grain yield all years kg/ha rel. kg/ha rel. kg/ha rel. kg/ha rel. 1. Early October 4 700 100 1 900 100 1 230 100 2 610 100 2. » November 4 890 104 2 340 123 1 070 87 2 770 106 3. » December 4 510 96 3 230 170 1 190 97 2 980 114 4. 20—40 cm snow 4 550 97 2 860 150 1 300 105 2 900 111 5. In spring after melting of snow 3 920 83 3 380 178 1 190 97 2 830 108 6. At normal application time 4 110 87 3 090 163 1 080 88 2 760 106 1967 1968 1969 Grain yields F = 5.32** F== 3.16* F = 0.43 sx 3.54 % 11.50% 11.53% 84 Table 8. Test with winter wheat during nitrogen application time. 1966—67 Soil type silty sandy clay. Nutrients in 1967 pH 5.9, Ca 3 100, P 8.8 and K 170 mg/1. Store fertilization with 1 000 kg/ha PK fertilizer (0-17-15) on the surface. Tests made with Linna wheat. Sown 3. 9. 66. Harvested 23. 8. Size of test plot 5 m X 50 m. 4 replications. As fertilizer 150 kg N/ha calcium ammonium nitrate. 1967—68 Soil type silty clay. Nutrients in 1967 pH 5.5, Ca 3 375, P 4.0 and K 290 mg/1. Fertilization in connection with seed-bed preparation: 600 kg compound fertilizer (8-13-9) and 500 kg PK fertilizer/ha by drilling. Tests made with Linna wheat. Sown 7. 9. 67. Harvested 22. 8. 68. Size of test plot 8 m X 30 m. 4 replications. In the fertilization 150 g/ha N as calcium ammonium nitrate has been used. 1968—69 Soil type clayeye sand and silt. Nutrinets in 1967 pH 5.8, Ca 2 025, P 4.8 and K 284 mg/1. Fertilization in connection with seed:bed preparation with 700 kg/ha compound fertilizer (15-25-10), by drilling. For shoots 150 kg/ha N as calcium ammonium nitrate. Tests made with Linna wheat. Sown 5. 9. 68. Harvested 12. 8. 69. Size of test plot 10 m X 50 m. 4 replications. (When coming into ear another 200 kg/ha calcium ammonium nitrate was given). Over- Grain yield winter 1 000 Raw Lodging observ. HI- g.w. Falling protein % 13. 4. 67. weight g number % Treatment kg/ha rel. covering o. 'o 1. Early October 2 610 100 17.195.5 76.933.3 262 11.7 17.395.5 78.933.2 253 12.2 21.996.0 78.935.6 256 12.6 15.096.2 79.334.2 249 12.2 27.595.5 79.035.1 266 12.6 25.396.5 78.135.2 258 13.2 2. » November 2 770 106 3. » December 2 980 114 4. 40 cm snow 2 900 111 5. In spring after melting of snow 2 830 109 6. At normal fertilizing time 2 760 106 F = 0.23 (different years F = 76.67***) The protein contents of the grain yield are smaller because of the nitrogen application in autumn than they would be after application in spring. A factor which may be of importance e.g. in the cultivation of malting barley. Concerning tests carried out elsewhere in Finland, the results over one year have been published in two experimental farms (Köylijärvi 1969, Varis 1969). In the tests Köyli- järvi carried out in Mietoinen in 1969, the spring application of calcium ammonium nitrate gave better results for winter wheat than application in autumn or early winter, but when broadcasting was used the December application of compound fertilizer (15- 20-15) gave a better result than spring application. In the tests carried out by Varis in Anttila, autumn application has given better results for winter wheat than spring applica- tion, but the protein contents have been lower respectively (11.4 and 12.5 %). A similar decline in protein contents has been noted in tests carried out in the U.S.A. (Stevenson et al. 1969). Paavilainen (1970) noted in the fertilization of marshland forest that part of the nitrogen fertilizer spread on snow late in winter was lost. 85 In the U.S.A. Aldrich (1969) has examined the spreading time of nitrogen on corn and found autumn application about as good as spring application in northern regions where the temperature of the soil is low in winter. Also tests in Hungary have given similar results for winter wheat in autumn and spring applications, when the autumn application has been given into frozen soil (Dudas et al. 1968). Nömmik (1966) in Sweden has also paid attention to nitrogen keeping over the winter. In Oregon, U.S.A., Cooper (1956) has found nitrogen given in spring and in autumn equally effective for hay. REFERENCES Aldrich, S. R. 1969. Fall application. Agr. Ghem. 24, 6: 12—14. Cooper, G. S. 1956. The effect of source, rate and time of nitrogen application on the yields, vegetative composition and crude protein content of native floodmeadow hay in eastern Oregon. Agr.J. 48: 543—545. Dudäs, F., Jelinek, K. & Pelikän, M. 1968. Method of fertilization with nitrogen in relation to yield and quality to winter wheat. Rostl. Vyroba 14, 5: 489—498. Elonen, P., Nieminen, L. & Kara, O. 1967. Tuloksia kevätviljojen sadetuksesta savimailla. Maat. ja Koetoim. 21: 7—17. Köylijärvi, J. 1969. Näinkin voi käydä . . . Koetoim. ja Käyt. 26: 37. Larpes, G. 1966. Rivilannoituksen vaikutus kevätviljoissa. Maat. ja Koetoim. 20: 14—20. —»— 1968. Rivilannoituskokeet vv. 1965—67. Maaseudun Tulevaisuus 52. 12. 58—59. Nieminen, L., Kara, O. & Elonen, P. 1967. Kokemuksia sijoituslannoituksesta. Maat. ja Koetoim. 21: 42—49. Nömmik, H. 1961. Kalium- und ammoniumfixierung in schwedischen Ackerböden. K. skogs- och lantbr. akad. tidskrf. Suppl. 5: 28—39. —»— The residual effects of nitrogen fertilizers in relation to the quantities of mineral nitrogen recovered in the soil profile. Acta Agric. Scand. 16: 163—178. Paavilainen, E. 1970. Tutkimuksia levitysajankohdan vaikutuksesta nopealiukoisten lannoitteiden aiheut- tamiin kasvureaktioihin suometsissä. Folia Forest. 75: 1969. Pessi, Y. 1969. Typpilannoitteiden syyslevityksestä. Leipä leveämmäksi 4: 29—31. —»— Ylänen, M., Leskelä, A. & Syvälahti, J. 1970. Results of tests made with placement fertilization on the Kotkaniemi experimental farm. J. Sci. Agric. Soc. Finl. 42: 193—202. Stevensson, C. K. & Baldwin, D. S. 1969. Effect of time and Method of Nitrogen Application and Source of Nitrogen on the yield and Nitrogen Content of Corn. Agr. J. 61: 381—384. Varis, E. Syysvehnän laadusta vehnän tuotannon pulma? Pellervo 70: 1186—1187. SELOSTUS TYPPEÄ SISÄLTÄVIEN LANNOITTEIDEN SYYS- JA TALVILEVITYKSESTÄ SUOMESSA Yrjö Pessi, Mikko Ylänen, Auvo Leskelä ja Jorma Syvälahti Rikkihappo Oy, Helsinki Viljoille annettavan typen levitysajan tutkimiseksi on Kotkaniemen koetilalla Vihdissä järjestetty useita kokeita vuodesta 1965 lähtien. Kokeet on tehty tiiviillä savimailla, joilla typen kulkeutuminen on oletettu hitaaksi. Kevätviljoilla typen syyslevitys marraskuussa routaantuneelle maalle on antanut hyvän satotuloksen. Sadon valkuaispitoisuus syksyllä typen saaneilla alueilla on alempi kuin keväällä levitetyillä alueilla. Syysvehnällä on joulukuun levitys antanut keskimäärin parhaan sadon, mutta valkuaispitoisuuden aleneminen on luettava haitaksi. Rukiilla on kevätlannoitus antanut keskimäärin parhaan sadon. Lakoutu- minen on kuitenkin syys levityksessä ollut selvästi vähäisempää kuin keväällä typen saaneilla alueilla.