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  • The irrigation influence under the soil, microclimate and plants in maize from Crişurilor Plain
    180-186
    Views:
    70

    The paper is based on the researches carried out in the long term trial placed on the preluvosoil from Oradea in 1976, for establishing
    the soil water balance. In the irrigated variant the soil moisture was determined 10 to 10 days for maintaining the soil water reserve on
    irrigation depth (0 – 50 cm for wheat and bean, 0 – 75cm for maize, sunflower, soybean, sugarbeet, potato and alfalfa 1st year and 0 – 100
    cm for alfalfa 2nd year) between easily available water content and field capacity. Thus, an average irrigation rate of 2560 m³/ha was used
    in the 9 experimental crops. The average of the annual rainfall for the 1976 – 2008 period was of 625.0 mm. The technologies used were
    correlated with the needes of the crops, such as melioration crop rotation, chemical fertilizers in accordance with the chemical export on the
    yield, manure (40 t/ha) was used in potato and sugarbeet. After 33 years of the irrigation use the soil structure degree (38.62%) did not
    decrease when compared to the unirrigated maize – wheat crop rotation (37.01%). Bulk density, total porosity, penetration resistance and
    hydraulic conductivity have worse values than the ones in the unirrigated variant. The humus content is very close to the humus content
    determined in 1976, the phosphorus and the potassium content increased very much in comparison with the initial content (117 ppm vs 22.0
    ppm); (180.0 ppm vs 102 ppm). The use of the adequate fertilization system and of the irrigation water with a good qaulity did not determine
    a decrease of the pH value of the soil. The irrigation determined the improve of the microclimate conditions, the increase of the plant water
    consumption, yield gains very significant statistically and higher protein content of the maize grains.

  • Researches regarding the influence of the some technological elements on water use efficiency in maize from Crisurilor Plain
    5-9
    Views:
    135

    Plain and the influence of the hybrid, plant density, crop rotation, nutrient supply, weeds and irrigation on water use efficiency were studied.

    Choosing of the hybrid with the best water use efficiency is very important because a hybrid from 500–600 FAO group (Fundulea 376) in unirrigated conditions and a hybrid from FAO group over 600 (Fundulea 365) obtained the biggest water use efficiency; the hybrid Fundulea 365 obtained the highest irrigation water use efficiency, 20.1 kg yield gain 1 mm-1 irrigation water.

    One of the most known hybrid in the area is Turda super and the highest water use efficiency was obtained using the plant density of 55 000 plants/ha in unirrigated variant and 70 000 plants/ha in irrigated variant. The highest irrigation water use efficiency, 20.7 kg yield gain 1 mm-1, was obtained at 70 000 plants ha-1.

    In maize monoculture was obtained the lowest values of the water use efficiency in unirrigated and irrigated variant: in the wheat-maize crop rotation the values were higher than in maize monoculture and in the wheat-maize-soybean were registered the highest values. The same situation was registered regarding the irrigation water use efficiency.

    Farm manure (30 t ha-1) and especially manure (30 t ha-1) +chemical fertilizers (N90P45) determined a higher values of the water use efficiency in comparison with the control. In the variant with organic + mineral fertilization was registered the higher value (19.4 kg yield gain mm-1) of the irrigation water use efficiency.

    Water use efficiency was much lower in the variant with weeds in comparison with the variant without the weeds; the differences were of 69% in unirrigated variant and of 64% in irrigated variant, very significant statistically. Irrigation water use efficiency from variant with weeds was lower than the value registered in the variant without weeds; the difference (68%) was very significant statistically.

    In average in period 1976–2012, the irrigation determined the increasing in water use efficiency with 22%, 19.4 kg mm-1 vs. 15.8 kg mm-1, but not in all the years caused the irrigation increasing in water use efficiency in comparison with unirrigated maize.

    The results research emphasized the need of the optimization for technology elements studied and a better water use efficiency will be obtained.