engleski

Effects of rates and depths of irrigatio on maize properties

A field trial was established accordind to the split-plot method in the region of \akovo (Budrovci, 1993, Krndija, 1994, Budrovci, 1995) from 1993 to 1995. The main factor (A) was irrigation rate consisting of 4 variants (50 mm, 40 mm, 30 mm and 20 mm), while the fifth variant was a control plot (without irrigation). The sub-factor (B) were maize cultivars of the FAO group 500 (OsSK 552, OsSK 554, Bc 588B and Bc 5982). We examined the water content in soil at depths 10 cm, 20 cm and 30 cm. On the basis of these results, we determined the time of irrigation. Irrigation was intiated when the water content in soil, was observed at 30 mm irrigation, amounted to 70% of the field capacity. Irrigation was performed by using a self-propelled sprinkler which is often called "tiphon" in practice. The quality of water used for irrigation belonged to the C1-S1 class and it may be used safely without a possibility of soil salting or alcalization. The water content in soil was optimum when soil was irrigated at depth of 30 mm and 40 mm and it ranged from 70 to 100% of field capacity measured up to 30 cm depth. The yield of maize kernels (t/ha) was significantly or highly significantly higher in all irrigation rates, as compared to the control plot. The maize cultivars did not show any significant yield differences over the course of the investigation.The average maize yield over three years of the investigation was 9, 043 t/ha on the control plot and a) 11, 081 t/ha (the variant at the depth of 20 cm), b) 12, 359 t/ha (the variant at the depth of 30 mm), c) 13, 723 t/ha (the variant at the depth of 40 mm) and d) 14, 640 t/ha (the variant at the depth of 50 mm). The average yield increase per each variant of irrigation over the years was 2, 04 t/ha (20 mm - 22, 5%), 3, 31 t/ha (30 mm - 36, 5%), 4, 86 t/ha (40 mm - 53, 7%) and 5, 60 t/ha (50 mm - 61, 8%). Regression equations have shown that the maize yield (t/ha) is postively correlated with the height of ear, the plant height and the number of ears per plant.

Irrigation rates; maize; depths of irrigation; field capacity; soil water properties

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