The influence of sprinkler irrigation and four nitrogen fertilization doses on the height of true millet cv. ‘Gierczyckie’ was determined in a field experiment carried out in the years 2005–2006 on a very light soil at Kruszyn Krajeński near Bydgoszcz. The soil in horizon 0–50 cm was characterized by field water capacity 57 mm, useful retention 43 mm and effective useful retention 30 mm only. The experiments were run in a split-plot system with three replications. Two different factors were compared. The first row factor – irrigation, was used in the two following treatments: Wo – without irrigation (control), W1 – sprinkler irrigation according to tensiometer indications (-0,03 MPa). The second row factor – differentiated nitrogen fertilization, was used in the four following variants (doses): N0 = 0 kg N ha -1, N1 = 40 kg N ha -1, N2 = 80 kg N ha -1, N3 = 120 kg N ha -1. Water requirements of true millet were estimated as optimal rainfall amounts for this crop, according to Klatt and Press proposals. Mean - for two seasons - water needs of true millet (since May 1 to August 31) amounted 278 and 294 mm, for Klatt and Press proposals, ...
Two soil profiles at Kruszyn Krajeński near Bydgoszcz were studied at the paper. Characteristic of soils and their water properties were determined. Air temperature (t) values and rainfall amounts (P) in particular months of vegetation period (April–September) in 1997–2006 for the investigated area were given. The vegetation period was characterized by mean air temperature 14,4 °C, ranging in particular years from 13,4 to 15,2 °C. Rainfall total during the vegetation period amounted on average 283,4 mm, ranging from 177,5 to 377 mm. Potential evapotranspiration (Etp) amounts were also determined using Grabarczyk’s formula. Irrigation requirements under the considered soil-climatic conditions were determined according to the following Drupka’s proposal: rainfall total (P) in the vegetation period as well as potential evapotranspiration (Etp) and difference Etp – P. Irrigation is needed when rainfall is lower than 370 mm, Etp is higher than 515 mm, and difference Etp – P is higher than 150 mm. On the base of rainfall amounts in vegetation period it can be stated that in years 1997-2006 irrigation requirements have been occurred in 8 seasons, and in two remaining years irrigation also could be needed because rainfall amounts were slightly higher from 370 mm (only by 4 and 7 ...
In this studies, a plant water needs index was defined as an amount of rainfall, in the period of plant increasing water demands, which didn't increase a yield of an irrigated plants. Such defined optimal rainfall was calculated on the basis of results of long-term field experiments carried out on two kinds of soil in a region of Bydgoszcz. Irrigation needs understood as rainfall insufficiency in the period of plant increasing water demands, were calculated as a difference be-tween optimal and actual rainfall. Homogeneous rainfall data from years 1971-2005 in Mochełek (placed near Bydgoszcz) were used. Calculations of irrigation needs were made in the period of increasing water demands of the followed plants: spring cereals, medium-early potato and maize cultivated for grain. All of them were grown on two kinds of soil: a very light soil of permeable subsoil and a light soil of compact subsoil. Obtained results enabled to classify the evaluated irrigation needs. The criterions were: a number of essential individual water doses and a quantity of forecasted productive effects of the irrigated plants. Re-sults of the studies show that the irrigation needs calculated on a very light soil in the region of Bydgoszcz occurred in 87,7-97,1% (it ...
