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Sirvi Autor "Litke, L." järgi

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  • Pisipilt
    Kirje
    Effect of nitrogen fertilization on winter wheat yield and yield quality
    (2018) Litke, L.; Gaile, Z.; Ruža, A.
    Wheat ( Triticum aestivum L.) is the most common cereal, which is grown in Latvia. Nowadays, farmers are trying to get high grain yields in line with food quality, at the same time trying to minimize production cos ts and to use environmentally friendly technologies. The objective of this experiment was to clarify the impact of nitrogen fertilization on winter wheat yield and yield quality under two soil tillage systems and after two forecrops. Trials were conducted at the Research and Study farm ‘Peterlauki’ of Latvia University of Agriculture (56 ° 30.658 ’ N and 23 ° 41.580 ’ E). Researched factors were (1) crop rotation (wheat/wheat and oilseed rape ( Brassica napus ssp. oleifera )/wheat), (2) soil tillage (traditional soil tillage with mould - board ploughing at a depth of 22 – 24 cm and reduced soil tillage with disc harrowing at a depth below 10 cm ), (3) nitrogen fertilizer rate (altogether eight rates: N0 or control, N60, N90, N120(90+30), N15 0 (90+60) , N180 (90+60+30) , N210 (90+70+50) , and N240 (120+60+60)), and (4) conditions of the growing seasons 2014/2015, 2015/2016 and 2016/2017. The results indicate that winter wheat yield has been significantly affected by soil tillage, nitrogen fertilizer rate ( p < 0.001) and forecrop ( p < 0.05). Three - year research confirmed significant yield increase until the nitrogen fertilizer rate N180. Significantly higher average grain yield was obtained under traditional soil tillage. Nitrogen fertilizer affected significantly all tested yield quality indicators ( p < 0.001) . Increase of nitrogen fertilizer rate secured significant increase of winter wheat grain quality indices, except starch content, after both forecrops and in both soil tillage variants. Values of yield quality indicators increased significantly enhancing N - rate from N150 up to N 210.
  • Pisipilt
    Kirje
    Effect of nitrogen rate and forecrop on nitrogen use efficiency in winter wheat (Triticum aestivum)
    (2019) Litke, L.; Gaile, Z.; Ruža, A.
    Application of plant nutrient is one of the most important measures increasing grain yield and yield quality. Excessive application of nitrogen fertilizers leads to nitrogen leaching and it affects the quality of groundwater and surface water. The objective of this research was to evaluate the effect of nitrogen fertilizer rate on nitrogen use efficiency in winter wheat after two forecrops. The experiment was conducted at the Research and Study farm ‘Pēterlauki’ of Latvia University of Life Sciences and Technologies (56° 30.658’ N and 23° 41.580’ E) in four growing seasons: 2014/2015, 2015/2016, 2016/2017 and 2017/2018. Researched factors were crop rotation (wheat/wheat and oilseed rape (Brassica napus ssp. oleifera/wheat) and five nitrogen fertilizer rates (kg ha-1 ): N0 or control, N60, N120(90+30), N180(90+60+30) and N240(120+60+60). Nitrogen fertilizer affected winter wheat grain yield significantly (P < 0.001) and average grain yield increased significantly (P < 0.049) until nitrogen rate N180. But analyzing it after each forecrop separately, yield increased significantly (P < 0.05) until N120 after both forecrops. Nitrogen fertilizer affected nitrogen use efficiency (NUE), nitrogen uptake efficiency (NUpE), nitrogen utilization efficiency (NUtE) and protein content significantly (P < 0.001). When increasing nitrogen fertilizer rate NUE, NUpE and NUtE decreased, and higher results were observed at the lowest nitrogen rates. Increased nitrogen fertilizer rate also increased crude protein content in grain, and for bread baking suitable grain was obtained only with the highest N rate: N 240. Forecrop did not affect winter wheat grain yield, however, it affected NUtE (P < 0.01), NUE (P < 0.001) and nitrogen harvesting index (P < 0.001) significantly; higher results were observed when wheat was grown after wheat.