<strong>AGRONOMIJAS</strong> 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
<strong>AGRONOMIJAS</strong> VĒSTIS (Latvian Journal of Agronomy), No.10, LLU, 2008Under the influence of plant feeding with potassium magnesia and potassium sulphate theamount of green proteins and green fats essentially increased in ecologiacally cultivated perennialherbage and kieserite feeding caused an essential increase only in green proteins. In the conditionsof intensive farming, nitrogen fertilizers are known to increase the amount of green proteins most.The effect of potassium on the harvest of perennial herbage and its quality mostly depended on theamount of potassium in soil. Potassium had little effect on the chemical composition of herbage(Daug÷lien÷, Arlauskien÷, 1989; Vasiliauskien÷ et al., 1996).Fertilization with potassium magnesia, potassium sulphate and kieserite did not have effecton the botanical composition of ecologically cultivated perennial herbage. Under the circumstancesof intensive production it was found that botanical composition on the sward deteriorates as a resultof onesided fertilization with nitrogen and potassium fertilizers (Vasiliauskien÷, Dapkus, 1990;Vasiliauskien÷ et al., 1996).ConclusionsFertilizing with a K 90 S 51 Mg 30 rate of potassium magnesia , essentially increased 0.73 – 1.30t ha -1 or 16.5 – 33.8 per cent the harvest of hay, 0.71 – 1.16 per cent the amount of green proteins,and 0.31 – 0.43 per cent the amount of green fats, compared to herbage with no fertilizers appliedand to fertilization with a rate of K 30 S 17 Mg 10 . Fertilization with a K 90 S 32.4 rate of potassium sulphateessentially 0.98 – 1.27 t ha -1 or 23.7 – 32.9 per cent increased the hay harvest compared tounfertilized herbage and fertilization with K 30 S 10.8 .Fertilization with rates of K 30 S 10.8 – K 90 S 32.4 essentially increased the amount of greenproteins compared to the greates rate of potassium sulphate of K 120 S 43.2 and unfertilized herbage.The amount of green fats essentially increased only compared to unfertilized perennial herbage.Kieserite fertilizers did not have effect on the harvest of perennial herbage, however it increasedthe amount of green proteins in it.Fertilization with potassium magnesia and potassium sulphate slightly incresed the amountof grasses in the botanical composition of perennial herbage, however they decreased the amountof legumes. On the contrary, kieserite caused an increase in legumes and a decrease in the amountof grasses.Referentes1. Blagoveschensky G.V. (2000) The productivity of grasslands in Russia, Conventional and ecologicalgrassland management: Procceedings of the international sumposium, 49-55.2. Csatho P., Debreczeni K., Sardi K. (2000) Correlation between soil K and winter wheat K contents in anetwork of Hungaria National long-term fertilization trials, Communications in soil Science and PlantAnglysis, 31, 2081-2092.3. Daug÷lien÷ N., Arlauskien÷ E. (1989) Skirtingų įvairiai azotu tręšiamų ganyklų žolynai, Žemdirbyst÷, 37,107-122.4. Daug÷lien÷ N. (1995) Agrocheminių savybių kitimas įvairios reakcijos vel÷niniame jauriniamedirvožemyje, priklausomai nuo ganyklos tręšimo, LŽI mokslo darbai, 48, 145-153.5. Daug÷lien÷ N. (2002) Žolininkyst÷ rūgščiuose dirvožemiuose, Lietuvos žemdirbyst÷s institutas, 261.6. Juraitis V. (1997) Daugiamečių varpinių žolių maisto medžiagų ir cheminių elementų kiekio kitimasvegetacijos laikotarpiu, Veterinarija ir zootechnika, 3 (25), 90-93.7. Juraitis V. (1998) Maisto medžiagų ir cheminių elementų kiekio kitimas daugiamet÷se ankštin÷se žol÷seper vegetaciją, Veterinarija ir zootechnika, 5 (27), 98-100.8. Pekarskas J. (2005) Ekologinio ūkininkavimo įtaka dirvožemio agrochemin÷ms savyb÷ms ir augalųmitybos problemų sprendimas, 107.9. Vasiliauskien÷ V., Brunien÷ L., Butkuvien÷ E. (1986) Metin÷s kalio trąšų normos paskirstymas ganiavomsskirtingų dirvožemių ganyklose, Žolių ūkis: mokslo darbai, 34, 23-33.10. Vasiliauskien÷ V., Dapkus R. (1990) Rates of Nitrogen and their distribution duribg the vegetation ofpasture swards of different earliness, Soil – Grassland – Animal Relationships, 267-271.11. Vasiliauskien÷ V., Kadžiulis L., Daug÷lien÷ N. (1996) Dirvožemio ir mineralinių trąšų įtaka ganomų iršienaujamų žolynų derliui ir kokybei, Žem÷s ūkio mokslai, 2, 77-84.12. Кутузова A.A., Привалова K.H. (1982) Эффективнось калийных удобрений, Кормпроизводство, 3,14-15.155