The effect of peat replacement in horticulture media by willow (Salix viminalis L.) biomass compost for cucumber transplant production.

This research evaluated the usefulness of horticultural substrates prepared on the basis of compost from chipped willow without additives and with the addition of nitrogen and decomposing mycelium of the cellulose-lignin fraction of wood in the cultivation of cucumber seedlings. The produced composts were mixed in different proportions: mixture 1 (W1) - the proportion of compost without additives and compost prepared with the addition of nitrogen and mycelium was in the ratio of 50:50, mixture 2 (W2) - the proportion of compost without additives and compost prepared with the addition of nitrogen and mycelium was in the ratio of 75:25. The starting mixtures were used to prepare horticultural substrates with different components (peat - P, vermicompost - V) and additives: basaltmeal - B, biochar from deciduous wood - C. The components were added in varying proportions. A total of 29 different substrates were subsequently tested in the study. Plant showed that the traits assessed varied to a greater extent under the effect of the test factors than at earlier growth stages. It was demonstrated that cucumber grown on substrates with 75% or 50% willow compost had a unit weight at the same statistical level as when grown on peat substrate (P). The plants with the highest unit weight (8.5- 10.4 g), belonged to the same homogeneous group and derived from sites W1P1B2, W2P1, W1P1B1, W2P2, W1P1C1, P, W1P1, W2B1, W2P2B2. High-quality cucumber transplant should characterise well develop, optimal height-to-stem thickness ratio, short hypocotyl, thick green leaves and cotyledons.

Compost from willow biomass (Salix viminalis L.) as a horticultural substrate alternative to peat in the production of vegetable transplants.

Willow (Salix viminalis L.) is a species well adapted to the environment conditions of central Europe. It is mainly cultivated for energy purposes as solid fuel. In this study, an evaluation of its suitability for other purposes was made using a 4-year old short rotation coppice (SRC) willow regrowth to produce chipped biomass which was composted. Four composting methods were used: without additives (WC), with the addition of nitrogen to narrow the C:N ratio (WN), with the addition of mycelium (WPG) and with the addition of mycelium and nitrogen (WPGN). A mixture of WC and WPGN composts was also prepared at 75:25% and 50:50% by volume. Composts, different proportion (25, 50 and 75%) of peat (SM) were evaluated for suitability as a substrate for tomato and cucumber transplant production. Tomato transplants produced in the medium were prepared from mixtures of willow composts (WPGN + WC(1) and WPGN + WC(2) and these mixtures with peat (WPGN + WC(1):SM and WPGN + WC(2):SM) were characterised as having the best parameters: plant height, lateral leaf span and number of leaves. Similarly, for cucumber transplants, better growth conditions than in peat substrate were obtained in the variant WPGN + WC(1) and WPGN + WC(1):SM. The addition of nitrogen to the composted biomass positively influenced the composting process. N concentration in the substrate was too high and toxic for the growth of tomato and cucumber transplants. At the end of the tomato and cucumber experiment, the nitrate content was 1510 and 2260 mg dm-3, respectively, in the WN substrate. Similarly, the high N-NO3- content in the composted willow substrate with the addition of nitrogen and mycelium did not promote the growth of tomato and cucumber. Based on this research at least 25% of the mass of the peat can be replaced by different willow composts without having an adverse impact on seedling growth and with some of the willow compost mixtures this could be as high as 50%.

Tuber yield and water efficiency of early potato varieties (Solanum tuberosum L.) cultivated under various irrigation levels.

This study aims to determine the effects of differences in variety and irrigations levels on potato yield (appropriate humidity, temperature, shading the plants from the sun if necessary) on potato yield in greenhouse conditions. Functions of potato production with respect to water use were developed for five dates of measurements of plant growth, in relation to the various vegetation phases. On the basis of potato vegetation phases, the potato water demand was determined. An experiment was conducted using the randomized sub-block method. The first order factor were the two varieties of potato that were grown under drip irrigation with three water regimes as a second factor experiment: level 1 (pF 2.7), level 2 (pF 2.5) and level 3 (pF 2.2). The variety had a significant effect on the weight of potato tubers. The irrigation level had only a significant effect on the total potato biomass. The potato harvest date had a significant effect on both of the examined treatments. The growth dynamics of the aboveground part and potato tubers were the highest in conditions of constant level 1. Regardless of the variety studied, on level 3 caused a reduction in potato biomass production.The highest water consumption was observed during the tuber potato growth period to flowering. The values were varied from 0.39 l/pot day level 1 (in both investigated cultivars) to 0.99 l/ pot/day (humidity level 3 for Julinka cultivar) in July. The most intensive increase in water consumption was observed at the level 3. The average W index of the average daily water dose calculated for Denar cultivar amounted 0.40 l day-1 in the first period (O1) to 0.79 l day-1 in the fifth period (O5) and for Julinka cultivar 0.49 l day-1 (O1) to 0.92 l day-1 (O5). Stress due to water shortage and/or excessive levels of water in the soil negatively influenced the yield of potato tuber. Potato varieties reacted differently to soil water content.

Influence of variation in the volumetric moisture content of the substrate on irrigation efficiency in early potato varieties.

Potato is a plant with high water requirements. This factor affects not only the weight of potato tubers but also their quality parameters. In order to achieve quantity and quality goal, it is helpful if we apply the principles of precision agriculture, which also contributes to sustainable management of environmental resources. Accurate identification of the water requirements of crops is the basis for determining optimal irrigation doses and dates. After their application, it is possible to assess the effectiveness of irrigation treatments and their impact on the air-water conditions in soil with a root system. The aim of the presented study was to analyse the influence of volumetric soil moisture diversity on the vegetation of early potato varieties. Two potato varieties were subject to investigation: Denar and Julinka. Pot experiments were carried out at the Department of Horticulture of Wroclaw University of Environmental and Life Sciences. Three variants were analysed: one with a low water content in the soil (pF 2.7), one with the optimal water content (pF 2.5) and one with a high water content (pF 2.2). The basis for the selection of the frequency and application rate of water doses was soil moisture measured with an SM150-Kit set. Volumetric moisture was measured with a TDR apparatus. It was found that the water requirements of both potato varieties differ and increase along with the development of the aboveground and underground parts. Moreover, it was shown that the irrigation requirements of cv. Julinka are higher than those of Denar (31.4-33.0% higher), depending on the adopted variant. The research also showed that the most effective method of potato cultivation is to maintain soil moisture at a lower level. This should be taken into account in regions where the cultivation of this species uses supplementation of the water requirements by irrigation.