AGRONOMIJAS VĒSTIS - Latvijas Lauksaimniecības universitāte

AGRONOMIJAS VĒSTIS (Latvian Journal of Agronomy), No.10, LLU, 2008Table 3. Effect of potassium sulphate rates on the harvest and chemical composition of perrenialherbage.No. Index K 0 S 0 K 30 S 10.8 K 60 S 21.6 K 90 S 32.4 K 120 S 43.2 LSD 051. Harvest of 3.85 4.14 4.59 5.12 4.82 0.69hay, t ha -12. Green 11.74 13.11 13.15 12.64 11.98 0.41proteins, %3. Green fats, 0.86 1.04 1.21 1.27 0.94 0.37%4. Green fibre, 31.14 30.36 29.85 29.91 31.29 2.32%5. Greenashes, %2.08 2.14 2.21 2.43 2.31 0.62Table 4 Effect of potassium sulphate rates on botanical composition of perennial herbageNo. Index K 0 S 0 Mg 0 K 30 S 10,8 K 60 S 21,6 K 90 S 32,4 K 120 S 43,2 LSD 051. Clover, % 85.08 85.48 85.03 84.74 84.41 6.422. Grasses, % 12.81 12.76 13.46 13.60 14.14 2.073. Other herbage, % 2.11 1.76 1.51 1.66 1.45 0.72The greatest harvest of the first year’s perennial herbage was obtained by fertilizingherbage with a Mg 120 S 32.4 rate of kieserite. Kieserite fertilizers did not have essential effect on theharvest of first year’s perennial herbage. Fertilization with kieserite caused an essential increase inthe amount of green proteins but there was no essential effect on the amount of green fats, fibre andashes in the hay of perennial herbage. Fertilization caused a slight decrease of grasses, howeverthere was a slight increase in legumes in the botanical composition of the sward (see Tables 5-6).Table 5 Effect of kieserite rates on the harvest and chemical composition of perrenial herbageNo. Index Mg 0 S 0 Mg 30 S 24 Mg 60 S 48 Mg 90 S 72 Mg 120 S 96 LSD 051. Harvest of 4,33 4,34 4,35 4,46 4,51 0,42hay, t ha -12. Green 11,75 12,43 12,55 12,41 12,47 1,13proteins, %3. Green fats, 1,22 1,28 1,26 1,36 1,22 0,28%4. Green fibre, 30,11 28,51 28,91 29,14 28,67 2,34%5. Greenashes, %3,27 2,58 2,66 3,12 3,20 1,12Table 6 Effect of kieserite rates on botanical composition of perennial herbageNo. Index Mg 0 S 0 Mg 30 S 24 Mg 60 S 48 Mg 90 S 72 Mg 120 S 96 LSD 051. Clover, % 82,94 84,22 83,63 83,96 84,68 7,122. Grasses, % 16,50 15,24 15,87 15,45 14,68 2,643. Other herbage, % 0,56 0,54 0,50 0,59 0,64 0,18DiscussionsInvestigating the effect of potassium magnesia, potassium sulphate and kieserite on theharvest of perennial herbage, we found that when optimum rates K 60-90 of fertiliazers were appliedthe harvest increased 32.9 – 33.8 per cent. Similar results were obtained in Russia(Blagoveschensky, 2000). It was determined in the way of investigation that for the soils of theecological farms medium in potassium the optimum potassium rate would be K 60-90 and there is noneed to increase it. According to the research carried out by different authors, the optimum rate ofpotassium under the circumstances of intensive farming is K 100-150 or K 60-120 (Кутузова,Привалова, 1982; Vasiliauskien÷ V. et al., 1986).154