Browsing by Subject "ravinnepitoisuus"
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(2019)Research on phosphorus (P) fertilization of white cabbage has been limited even though white cabbage is an important field vegetable in Finland. The quantities of phosphorus recommended in Finland when cultivating white cabbage are relatively large and excessive fertilization increases the risk of runoff to water systems. Scientific research is needed to determine fertilization levels that ensure good yields while reducing risks to the environment. The effects of P fertilization on yield, phosphorus uptake and phosphorus balance of white cabbage were studied in two soils of different P status in Piikkiö, Finland. The experiment on soil with loamy sand texture and high P status consisted of four fertilization treatments between 0-32 kg P ha-1 while the experiment on clay parcel with relatively low P status consisted of five treatments between 0-100 kg P ha-1, including a starter treatment. Yield, plant P content and P uptake were unaffected by the treatments. Yield was 83-87 t ha-1 on high P soil and 66-69 t ha-1 on low P soil. In high P soil, uptake of P by the plants was 50 kg ha-1 and field P balance was negative in all treatments. In low P soil, uptake was 40-45 kg ha-1 and P balance was positive starting from treatment level 30 kg P ha-1. It is likely that P fertilization levels based on the maximum limits set by the national Agri-environmental Programme are unnecessarily high for white cabbage. A level of fertilization equaling the P uptake of the yield can be recommended.
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(2019)Research on phosphorus (P) fertilization of white cabbage has been limited even though white cabbage is an important field vegetable in Finland. The quantities of phosphorus recommended in Finland when cultivating white cabbage are relatively large and excessive fertilization increases the risk of runoff to water systems. Scientific research is needed to determine fertilization levels that ensure good yields while reducing risks to the environment. The effects of P fertilization on yield, phosphorus uptake and phosphorus balance of white cabbage were studied in two soils of different P status in Piikkiö, Finland. The experiment on soil with loamy sand texture and high P status consisted of four fertilization treatments between 0-32 kg P ha-1 while the experiment on clay parcel with relatively low P status consisted of five treatments between 0-100 kg P ha-1, including a starter treatment. Yield, plant P content and P uptake were unaffected by the treatments. Yield was 83-87 t ha-1 on high P soil and 66-69 t ha-1 on low P soil. In high P soil, uptake of P by the plants was 50 kg ha-1 and field P balance was negative in all treatments. In low P soil, uptake was 40-45 kg ha-1 and P balance was positive starting from treatment level 30 kg P ha-1. It is likely that P fertilization levels based on the maximum limits set by the national Agri-environmental Programme are unnecessarily high for white cabbage. A level of fertilization equaling the P uptake of the yield can be recommended.
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(2014)Tillage and sowing methods impact on the nutrient balances which is an interest of researchers and farmers. An aim of the research is to compare nutrient balances of tillage and sowing. During the years 2000 – 2010 in Jokioinen, studies have been conducted concerning how different tillage and sowing methods affect spring cereal nitrogen and phosphorus balances in heavy clay soil. The compared tillage systems were autumn mouldboard (25 cm) plough, stubble cultivation (10 cm) and no-till. The sowing systems under comparison were combined rotovator and shoe coulter seeder and single and double coulters disk seeders. The measurement thinks were yield (seed and straw), nitrogen and phosphorus content. From the measured values were calculated N and P balances which included seed, nutrient and natural deposition. The range of nutrient balances was large during the experiment period. Average nitrogen balance of different tillage methods were: plough 41,3 kg/ha stubble cultivation (S) 40,1 kg/ha and no-till (N) 44,0 kg/ha. Average phosphorus balance were P -0,5, S -0,3 and N 0,1 kg/ha. Average nitrogen balance of different sowing methods were combined rotovator, single disk coulter (R) 43,7 kg/ha and double disk coulter (SK) 44,9 kg/ha. Average phosphorus balance were JK -1,1, R 0,2 and SK 0,3 kg/ha. The weather conditions, especially precipitation, effects strongly on nutrient balances of tillage methods. In dry conditions no-till reached better nutrient balances than the other tillage methods. In other hand, in wet conditions mouldboard plough were better than an average. The weather conditions did not affect nutrient balances of the sowing methods. Furthermore combined rotovator and shoe coulter seeder achieved almost without exception better nutrient balances than others sowing methods regardless of the growing season precipitation.
Now showing items 1-3 of 3