Vaaramoreenin lannoitus- ja kalkituskokeen tuloksia

anglais. At the Karelia Experimental Station (at Tohmajärvi) of the Society of Peat Cultivation the fertilizing and liming requirements of hill moraine (cf. KIVINEN 1941) have been studied in a long-term field test established in 1944. The effects of nitrogen, phosphorus and potassium given in artificial fertilizers on the crop yield were observed both without liming and when liming and farmyard manure were applied. The following test members were included: (A) Test member group without lime and without farmyard manure. Fertilizers: (1), N, P, K, NP, NK, NPK. and PK. N = 15 kg N per hectare as calcium nitrate, P = 21.9 kg P per hectare as superphosphate, and K = 66.4 kg K per hectare as potassium salt, annually. (B) Test member group in which ground limestone was applied at 2000 kg per hectare as top dressing on grass ley in the year the test was established (1944) and the same amount of limestone was given once again in 1951. Fertilizers as in test member group (A). (C) Test member group included in the tests in 1949. Farmyard manure fertilizing at 40.000 kg per hectare, repeated in 1962. Fertilizers as in test member group (A). The contributions of the different nutrients towards the crop yield increment achieved with NPK fertilizing were calculated by distributing the combined NPK effect evenly among the different main effects (Method I). The effects of the nutrients were also calculated from binary fertilizer combinations in the manner presented by TENNBERG (1939) (Method II). The spring cereals were treated as one group as the test years were too few to allow a separate study of the individual species. Barley and spring wheat occurred twice in the test and mixed peas and oats once. The test results are presented in Tables 1 and 2. Winter rye was present in the tests three times and spring rye once in 1961. The effect of phosphorus was favourable with rye (Tables 3 and 4). Timothy-clover grass was included in the test in the years 1944–1946, 1950–1952 and 1955–1958. The crop yields are stated as air-dry hay without aftermath yields, in Tables 5 and 6. Tables 7 and 8 contain the crop yield results of all plants. It was noted that the crop yield level and the increases in crop yield obtained with fertilizing as well as liming varied greatly in different years even with one and the same plant species. A combination of fertilizers affected the crop yield increments produced by different nutrients. Liming increased the crop yields and caused changes in the effects of the nutrients. Liming increased the amounts of soluble phosphorus in the soil (Table 11), and the increments in crop yield of grassland plants obtained with phosphorus fertilizing consequently decreased. The effect of potassium fertilizing was enhanced as result of liming. Farmyard manure increased the soluble potassium and phosphorus quantities. Farmyard manure dressing increased the crop yields of the treatments given onesided fertilizer additions, while its effect remained low in association with NPK fertilization (Table 9). Liming and PK fertilizing increased the percentage of clover in grass leys (Table 10). That of tufted hair grass was reduced as a result of diversified fertilizing and of liming. Nitrogen fertilization seems to have increased the porportion of couchgrass in the grass leys.

finnois. Suoviljelysyhdistyksen Karjalan koeasemalla Tohmajärvellä on tutkittu vaaramoreenin lannoitus- ja kalkitustarvetta pitkäaikaisella kenttäkokeella. Tällöin on todettu, että satotaso sekä lannoituksella ja kalkituksella saadut sadonlisäykset vaihtelevat vuosittain voimakkaasti samallakin kasvilajilla. Väkilannoitteilla saadut sadonlisäykset vastaavat parhaiten Etelä-Suomen hietamailta saatuja sadonlisäyksiä. Lannoiteyhdistelmällä on ollut vaikutusta eri ravinteilla saatujen sadonlisäysten suuruuteen. Kalkitus on lisännyt satoja ja on aiheuttanut muutoksia ravinteiden vaikutuksiin. Kalkitus on lisännyt liukoisen fosforin määriä maassa ja sen johdosta fosforilannoituksella saadut nurmikasvien sadonlisäykset ovat pienentyneet. Kalilannoituksen vaikutus on kalkituksen seurauksena tehostunut. Karjanlanta on lisännyt muokkauskerroksen liukoisen fosforin ja kalin määriä. Karjanlantalannoitus on suurentunut yksipuolisen väkilantalannoituksen saaneiden koejäsenten satoja, mutta NPK-lannoitusta käytettäessä sen vaikutus on jäänyt pieneksi. Kalkitus ja PK-lannoitus ovat lisänneet apilan osuutta nurmissa. Nurmilauhan määrä on pienentynyt monipuolisen lannoituksen ja kalkituksen seurauksena. Typpilannoitus näyttää lisänneen juolavehnän osuutta nurmissa.