Sijoituslannoituksen kehityksestä ja tutkimustoiminnasta Suomessa

The placement of fertilizer in connection with sowing of cereal has become very popular in Finland within the last 10 years. Today we generally place fertilizer and drill seed at the same time with a fertilizer placement drill, which drills seed to rows and places fertilizer between every other row. We also use machines, fertilizer and seed drills, with which the sowing and the fertilizer placement are done with the same coulters in different operations. Shares of the drill coulters can also be turnable so that one end is a fertilizer coulter and the other a seed coulter. The sale of fertilizer placement drills is at present about 10 times larger than the total sale of traditional seed drills in Finland. There have been many field experiments in the placement of fertilizer with spring cereals in Finland. The placement of fertilizer into a depth of 8—10 cm has increased grain yields of spring cereals on an average about 14 percent. The increase in grain yields has varied between 0—40 % in different yers. The placement of fertilizer has improved most the availability of nitrogen, next of potassium and then of phosphorus. The placement has also accelerated ripening. The crude protein content of the grain yield has decreased somewhat by the placement of fertilizer. Sprinkler irrigation did not appear to reduce the effect of placement of the fertilizer. These two methods form a highly efficient combination

Rehumaissin typpilannoituksesta ja sadetuksesta

Typpilannoitusmäärän ja lannoitustapojen vaikutusta rehumaissin sadontuottoon ja raakavalkuaisen määrään tutkittiin vuosina 1976—1978 ja vastaavasti sadetuksen ja lannoituksen vaikutusta v. 1978 Suitian tilalla Siuntiossa. Koetekijöinä olivat rivi- ja sijoituslannoitus sekä typpilannoitustasot. Sadetuskokeessa tutkittiin N-lannoitusmäärien ja -levitysaikojen vaikutusta satoihin. Typpilannoitustavalla, rivi- tai sijoituslannoituksella, ei ole ollut merkittävää vaikutusta rehumaissin kuiva-ainesatoon, raakavalkuaissatoon ja raakavalkuaispitoisuuteen. Typpilannoituksella 150N kg/ha kylvön yhteydessä annettuna saatiin suurimmat kuiva-ainesadot. Sitä suuremmat lannoitemäärät 2—3 erässä levitettynä eivät ole lisänneet satotasoa. Typpilannoitustason noustessa 100 N kg:sta/ha 250 N kg:aan/ha lisääntyivät sekä raakavalkuaispitoisuus että raakavalkuaissato merkittävästi. Sadetus lisäsi yhden kasvukauden tutkimuksissa rehumaissin satotasoa merkittävästi. Kokeessa käytetyt typpilannoitemäärät 120 ja 170 N kg/ha ovat antaneet sadettaen ja sadettamatta keskimäärin yhtä suuret sadot kuin 240 N kg/ha yhdessä tai useammassa erässä levitettynä. Sadetuksella myös raakavalkuaissadot olivat suurempia, mutta raakavalkuais-% keskimäärin pienempi kuin sadettamatta

Sprinkler irrigation on clay soils in southern Finland III. Effect on the quality of grain yield

In the present paper the effect of irrigation on the ripening and on the quality of grain yield in the dry summers 1964—1966 was studied. Both the ripening and the quality of grain were found to be highly dependent on the date of irrigation. There was a distinct transitional period, before which irrigation speeded up ripening, decreased the amount of green grains and improved hectoliter weights and »falling numbers». On the contrary, if irrigation was applied after this transitional period, ripening was retarded and the quality of grains was impaired in regard to these properties. This transitional period was in the experimental years about two weeks before ear emergence or about Midsummer. The optimum period of irrigation, in regard to both yield level and to its ripening and quality, was in the middle between sprouting and ear emergence and its length was about two weeks. Wheat, barley and oats all responded to the date of irrigation in about the same way. The placement of fertilizers into the depth of 8—12 cm speeded up ripening and improved hectoliter weights. Particularly, it decreased the unfavourable effect of too late irrigation. The rate of fertilizers had no great influence on the quality of grains. Irrigation did not increase the weight of grains, but it increased the number of grains. The main effect of irrigation was likely to be caused by the tillering of crops, and these adventitious shoots had time to ripen, if irrigation was applied at a sufficiently early stage of development. The crude protein content of both wheat, barley and oats was markedly decreased by irrigation independently of the date of it. This decrease was usually the greater the higher yield was obtained. The decrease in the crude protein content indicates a shortage of nitrogen which was likely to be caused by the scanty mobilizeable resources of nitrogen in the soils long cultivated without leys. Obviously, this unfavourable decrease in the crude protein content could have been prevented with heavy dressings of fertilizer nitrogen

Sprinkler irrigation on clay soils in southern Finland II. Effect on the grain yield of spring yereals

In the dry summers 1964, 1965 and 1966, irrigation experiments of spring cereals were carried out on clay soils in Southern Finland. The soils having a rather poor structure because of the long-term cultivation without leys, endured without slaking the irrigation which was applied with »slow sprinklers» in the nigh-time. Neutral irrigation water containing small amounts of soluble salts was taken from a brook and a lake. One irrigation of 30—37 mm, applied at the optimum date, increased the grain yields of spring wheat 600—1000 kg/ha or 25—50 % and those of barley and oats 1600 kg/ha or 50 %. Barley and oats were the experimental plants only in 1966, when the relative increase in yields of all the three cereals were of the same order, namely 50 %. The optimum date of irrigation did not very closely depend on the state of development of the cereals, since within 2—5 weeks from sprouting about equal increases in yield could be obtained. Barley and oats responded, however, best to the irrigation applied one week before ear emergence. The late irrigation which was applied three days after ear emergence was best utilized by oats. Thus, the right order to irrigate cereals was in 1966: wheat, barley and oats, in spite of the reverse order of the ripening of the crops. An irrigation at the stage of sprouting had no effect on yield, because the sprouting occured well also without irrigation. Irrigation produced higher increases in yield when higher amounts of fertilizer were used. Thus, the profitable influence of irrigation was at least partly based on the better recovery of fertilizer nutrients by plants. Placement of fertilizer into the depth of 8—12 cm postponed the optimum date of irrigation some days, because the crops were able to make use of placed fertilizer also without irrigation in the early part of the summer. Placement of fertilizer and irrigation together formed an advantageous combination, because the influence of the placement of fertilizer was most effective immediately after sprouting whereas the best period of irrigation began 2—3 weeks later. With these both means, in the best cases, the yields could be almost doubled

Sprinkler irrigation on clay soils in southern Finland I. Sprinkler irrigation, its technique and effect on soil moisture

During the last three years, 1964—66, investigations on sprinkler irrigation of spring cereals have been carried out. The experimental fields were clay soils in Southern Finland. Neutral river and lake waters containing small amounts of soluble salts were applied in the nighttime. The application rate of the rotary sprinklers used was 2.5—4 mm per hour with the radius of 12±2 m. With this technique the experimental soils having poor structure endured the irrigation without any crust formation. It was found that the sprinklers equipped with two nozzles distributed the water more uniformly than those with one nozzle. With the former sprinklers a fairly good uniformity was attained: The amount of water usually varied between 25 and 35 mm with an average of 30 mm, except in a relatively small area nearest to the sprinklers which received too much water and in the area at the greatest distance from the sprinklers with less than the average amounts of water. The soil water conditions were followed by gypsum blocks inserted at different depths. In each experimental year, within 2—3 weeks from sprouting, the available water in the top soils decreased to 50 per cent of the total capacity. This dry condition existed for two months in the years 1964 and 1966 and for one month in 1965. During these dry periods the top soils were near the wilting point for a long time, and in 1966 the available water was wholly exhausted. The influence of transpiration was effective also in deeper layers. In 1966, the soil reached the wilting point also at the depth of 40 cm and stayed at this condition for about one month. The effect of a 30—37 mm irrigation on the soil moisture conditions lasted only for 1—2 weeks. Thus, the rate of evapotranspiration was as much as 4 mm per day. The plants consumed water simultaneously from the whole root zone, yet, most effectively from the surface layers. The top soil (20 cm in thickness) which had reached the wilting point was not completely moistened by the amounts of water applied. This indicates the high capacity of clay soils to store water. It is also noteworthy that a part of irrigation water percolated to 40 cm before the soil at the depths of 10 and 20 cm had time to get to the field capacity. In experimental years, to ensure favourable moisture conditions to spring cereals several high applications of water would have been needed. This proves that also during the short growing season in Finland a serious shortage of water may occur

Adaptation of silage maize varieties under extreme northern growing condions in Finland

Trials with maize varieties from various places in the world were started in 1975. In preliminary trials in 1975, 280 varieties were tested. Between 19 and 23 varieties were selected for ordinary variety tests in 1976—78 at the University farm in Siuntio. Weather conditions, particularly average daily temperatures in 1975 were better than the long term averages, and in 1976—78 far below the average growing conditions. Dry matter yields of the seven harvested silage varieties in 1975 varied between 5.8 and 11.5 tons/ha. In 1976—78 the variation in DM yields was 3.8—8.0 tons/ha among 19—23 varieties. In 1975, 44 varieties out of 280 produced mature seed. Only one variety matured in 1978, but none in 1976—77. The developmental stage of silage maize is primarily determined by ear percentage and secondarily by DM %. In 1975 the average ear % of seven varieties was 49.1 %, in 1978 18.1 % and in 1976—77 only 4.0—5.7 % in DM. As a result of the variety tests promising varieties from Yugoslavia, France and Germany could be found. It can be concluded from the long term temperature data that with very early hybrid varieties a mature grain yield can be harvested twice in ten years. Good quality silage material can be harvested six times in ten years and a satisfactory crop can be obtained eight times in then years. The limiting factor for the growth and development of maize in Finland is the low average temperature of the growing season. Important but less significant is the length of the vegetative period, which is determined by the first killing frost in the fall. The temperature deficit is particularly critical at the beginning of the growing season

Management techniques of maize crop in the marginal growing area in Finland

Silage maize management studies were carried out in 1976—78 on the University farm in Siuntio in southern Finland. Seeding time trials in 1976—77 consisted of three different types of varieties seeded at four different times between May 11 and June 8. In 1978 three seeding dates were tested in relation to the seeding depth of the maize. Population density studies were carried out in 1976—77. As a result of the management studies it can be concluded that the weather conditions were so unfavorable that true differences could not be found because even the best alternative in the management technique did not give a satisfactory agronomic result. Seeding dates from May 15 to May 25 can be recommended. Relatively heavy frosts in early June (—4°C to—6° C) will hurt stands but they do not kill the plant. The advance earned with early planting is thus not totally lost through the frosts Seeding depths of 5 to 7 cm are recommended. Population densities more than 10 plants/m2 are not necessary for the maximum yield. In average or better than average growing conditions the planting densities of 6 to 8 plants/m2 could yield a more mature forage crop

Sadetuksesta ja sen kannattavuudesta viljanviljelytiloilla Etelä-Suomessa

vokkirjasto Aj-KDiss. : Helsingin yliopisto, 197