Effect of nitrogen fertilization on energetic yield of winter wh

EFFECT OF NITROGEN FERTILIZATION ON ENERGETIC YIELD OF WINTER WHEAT IN THE POTATO PRODUCTING AREA

Plant production is not only the consumer of energy, but also its producer, as in the process of photosynthesis the plant creates from energetically poor matter the mater rich in energy. It is not only the energy from sun radiation and water, what participates in the creation of rich in energy matter, but it is also the energy supplied into the process of production in a form of machines´ work, pesticides or fertilizers. One of the most demanding impute is nitrogen fertilizing, as 1 kg of nitrogen can be expressed in energetic balances by the value 80 MJ. Therefore I aimed in my work to the effecting of the total energetic yield (both grain and straws) of winter wheat by nitrogen fertlizing.

In the field experiments established in the years 1993 - 1995 in the potato producting I studied the total energetic yield by three cultivars of winter wheat: Simona, Sparta and Torysa. In the experiment I watched the acting of four variants of nitrogen fertilizing, where the two of them went out of constant nitrogen doses (0 and 105 kg per hectare) and two went of the newer trends in plant nutrition (Nan - soil analyse for nitrogen content and ARR- anorganic analyse of plants).

The gathered results show, that the statistically significant lowest amount of energy per hectare was found by Simona variety (263,09 GJ.ha-1) compared with varieties Sparta (475,21 GJ.ha-1) and Torysa (490,60 GJ.ha-1).

Application of nitrogen fertilization had statistically significantly increased the energetic yield of plant stands of all studied varieties compared with non-fertilized variant. Though, there was not found its conclusive effect upon energetic content in grain and straw of the wheat among fertilized variants.

The effect of the year 1993 when the total energetic content was statistically lowest compared with years 1994 and 1995.

The amount of the totally produced energy of individual cultivars related to 1 kg of applied nitrogen had statistically significantly decreased with its increasing doses, as the lowest mean value was found by variant 105 kg of N per hectare (3,94 GJ.kg-1 N) and, on the contrary, the highest one was by the variant, where the dose went out of Nan (9,12 GJ.kg-1 N).

The amount of accumulated energy related to 1 kg of applied nitrogen was not equal by studied varieties in particular years of the experiment.

From the gathered results it is perceptible, that statistically lowest values of this parameter were reached by Simona (2,80 GJ.kg-1 N) compared with varieties Sparta (5,14 GJ.kg-1 N) and Torysa (5,30 GJ.kg-1 N).

Most of energy per 1 kg of nitrogen was statistically conclusively found in 1994 compared with years 1993 and 1995.

In the conclusion it can be stated, that the applied nitrogen had positively shown in increase of total energetic yield of all studied varieties of winter wheat. Next it can be said that the higher dose of nitrogen lead to decrease of the rate of produced energy to the unit of supplied nitrogen mass compared with variants of lower nitrogen dose, that came out of Nan and ARR.

Autor: František Hnilička

Zdroj: Trendy v agropotravinárstve - vedecká konferencia z medzinárodnou účasťou 1. - 4.

November 1999. Acta fytotechnica et zootechnica vol. 2: mimořádné číslo, s. 136,

1999.