Yield of forage sorghum (sorghum vulgare pers) depending on preirrigation soil moisture and sowing method

Abstract

Yield of irrigated forage sorghum has been analyzed in order to determine the threshold of optimum soil moisture and the effect of irrigation in dependence of sowing method. The highest yield of forage (95.74 t/ha) was achieved with the preirrigation moisture of 70-75% of field water capacity (FWC). Therefore, this value is the threshold of optimum soil moisture for forage sorghum. The average yield for rainfed sorghum was 65.79 t/ha, and thus the irrigation effect was 45%. The sowing in rows 25 cm apart brought the yield of 88.48 t/ha. This yield was significantly higher than that obtained in the row distance of 50 cm, which was 78.59 t/ha. The highest absolute yield of forage of 102.59 t/ha was obtained with the preirrigation moisture of 70-75% FWC and the distance of 25 cm between the rows. In addition to yield of forage, we analyzed the number of plants per unit area number of internodes and stem height shortly before cutting, portions of stems and leaves in yield of forage and the contents of dry matter in stems and leaves.

Analiziran je prinos zelene krme sirka u uslovima navodnjavanja u cilju utvrđivanja donje granice optimalne vlažnosti zemljišta i efekta navodnjavanja pri različitom načinu setve. Najveći prinos zelene krme (95,74 t/ha) ostvaren je pri predzalivnoj vlagi 70-75% od PVK, stoga ova vrednost predstavlja donju granicu optimalne vlažnosti zemljišta za krmni sirak. Prosečan prinos u uslovima bez navodnjavanja iznosio je 65,79 t/ha, a efekat navodnjavanja bio je 45%. Setvom krmnog sirka na međuredno rastojanje od 25 cm ostvaren je prinos od 88,48 t/ha, značajno više u odnosu na setvu na 50 cm, gde je prinos iznosio 78,59 t/ha. Apsolutno najveći prinos zelene krme od 102,59 t/ha ostvaren je navodnjavanjem pri 70-75% PVK i setvom na 25 cm međurednog rastojanja.