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Effect of harvest date on structural carbohydrates and lignin content in meadow sward in different pluvio-thermal conditions

100%

Wróbel B. , Zielewicz W. , Paszkiewicz-Jasińska A. , Spychalski B. , Jakubowska Z.

Journal of Water and Land Development

2022

tom no. 55

60--66

The content of structural carbohydrates and lignin are important assessment criteria of the feed value of meadow plants. It is affected by many independent factors, including among others its development stage during the harvest as well as climatic conditions, especially the amount of rainfall. During the years 2014-2016, plant samples were harvested at weekly intervals, respectively five times from late April to late May. The effect of harvest date on cellulose, hemicelluloses and lignin contents was evaluated. The chemical composition of plants was varied, depending not only on harvest date but also on the year of study. Regardless of the course of meteorological conditions in subsequent growing seasons, the increase of cellulose (from 236.5 to 297.9 g∙kg-1 DM), hemicelluloses (from 159.3 to 210.8 g∙kg-1 DM), and lignin (from 31.5 to 43.1 g∙kg-1 DM) in the following dates of harvest were observed. These parameters were also positively correlated with the total rainfall from the begging of vegetation season to the date of plants sampling (R2 = 0.65, 0.12 and 0.44 for cellulose, hemicelluloses and lignin, respectively), and with the average daily air temperature in the moment of harvest (R2 = 0.66, 0.32 and 0.52 for cellulose, hemicelluloses and lignin, respectively). The cellulose and lignin content, regardless of the harvest date, were significantly higher in the first year of the study (2014), when moisture conditions for plant development were optimal.

Mathematical models use to yield prognosis of perennials on marginal land according to fertilisers doses

86%

Hryniewicz M. , Strzelczyk M. , Helis M. , Paszkiewicz-Jasińska A. , Steinhoff-Wrzesniewska A. , Roman K.

Journal of Water and Land Development

2021

tom no. 51

233--242

Models describe our beliefs about how the world functions. In mathematical modelling, we translate those beliefs into the language of mathematics. Mathematical models can yield prognose on the base of applied fertiliser dose. In this work results of finding yield mathematical model according to fertiliser (nitrogen) dose for perennials (willowleaf sunflower Helianthus salicifolious, cup plant Silphium perfoliatum and Jerusalem artichoke Helianthus tuberosus) on marginal land are presented. Models were described as normalised square equations for dependence between yield and fertiliser doses. Experiments were conducted in lisymeters and vases for willowleaf sunflower and cup plant. For Jerusalem artichoke experiments were done in vases only. All experiments have been doing during two years (2018 and 2019) for different fertilisers doses (45, 90 and 135 kg N∙ha-1) in three repetitions. From simulations maximal yield could be achieved for following fertiliser doses – willowleaf sunflower 104 kg N∙ha-1, cup plant 85 kg N∙ha-1 and Jerusalem artichoke 126 kg N∙ha-1.