The colour-fleshed potatoes represent a good raw material for the extraction of juices with a high content of biologically active compounds and a high antioxidant activity. The blue-fleshed potatoes turned out to be a rich source of total polyphenols, as they had approximately 3.5 times higher content of identified anthocyanidins. Regardless of anthocyanin composition, all juices made of colour-fleshed potatoes were highly stable. Both, high temperature, exposure time to these temperatures, and medium pH had no significant effect on changes in total polyphenols content of potato juices. The juices examined, especially these made of blue-fleshed potatoes, demonstrated a higher ABTS+ stability during their heating than during pH changes. In addition, a higher antioxidant activity of juices was determined at neutral and alkaline than at acidic pH value of the medium.Stability of compounds in potato juice E. Rytel et al.

Living mulches can play a crucial role in the protection of the soil against erosion, as well as biological and chemical degradation. Soil fertility and its physical properties, including soil structure, are of special importance to crops. Soil physical properties are affected, among other factors, by the type of tillage. In order to determine the effect of regenerative practice (living mulches) on soil physical properties, a two-factorial experiment was conducted. The first factor involved white clover and perennial ryegrass as an intercropping of eggplant. The second factor was the living mulches sowing term: three weeks before eggplant planting, at the time of planting and three weeks after eggplant planting. Covering eggplant inter-rows with living mulches reduced eggplant yield and was beneficial to soil structure and improved water resistance of soil aggregates. Perennial ryegrass had a slightly more advantageous effect on yield and improvement of soil physical properties, as compared to white clover. The greater eggplant fruit yield was obtained from vegetable grown without companion plants. The application of living mulches (especially Trifolium repens L.) caused a non-significant decrease in eggplant fruit yield. It was found that limiting the growth of seedlings sown on the first date result in a decrease in marketable fruit yield (on average 14%). A similar result occurred when living mulches were sown on the planting date of eggplants and difference between the yields was 4.3%. The first term of sowing living mulches—three weeks before eggplant planting—no significantly affected the mean weighted diameter of soil aggregate (MWDg), the water stability index (ΔMWD), the index of waterproof index (Wod) and the soil structure index (W). Later sowing terms resulted in the improvement of the majority of the parameters; however, this was not confirmed statistically. Soil with periodic mechanical treatment of inter-rows showed the 3–4% lower values of soil porosity, 3–16% increased compactness, as well as 28–30% lower indices soil structure and 28–30% for water resistance of soil aggregates compared to the living mulches system.

SummaryConducted research involved evaluation of selected soil properties in eggplant cultivation with the use of living mulches from white clover and perennial ryegrass. The mulching species were sown three weeks before eggplant planting, in the term of planting and three weeks after planting this vegetable. In half of August there was assessed stability of soil aggregates on the basis of the following indicators of: cloddiness (B), misting (S), structure (W) of the soil and mean weighed diameter of aggregates -the dry method (MWDa), as well as water stability ( MWD) and waterproof (Wod) index of soil aggregates and mean weighed diameter of aggregates -the wet method (MWDg). Cover plants did significantly decrease soil cloddiness indicator, while the earliest term of their sowing contributed to lowering of that parameter values by nearly 1/3 in relation to the data obtained for mechanically treated plots. Indicator of misting of the soil and soil structure index was higher for the soil of inter -rows covered with living mulches. It was noticed that longer term of covering interrows with white clover and perennial ryegrass improved soil structure. Living mulches improved mean weighed diameter of aggregates, determined according to the wet method, as well as indicator of aggregates waterproof and water stability index. After sowing white clover or perennial ryegrass three weeks before eggplant planting, mean weighed diameter of aggregates, measured with the use of the wet method, was higher by 29.0% and by 18.3% than the one characterizing the object with the last term of sowing and it was higher by 31.4% and 17.1% than the value determined for mechanically treated inter -rows. ΔMWD indicator for the soil covered with white clover and with perennial ryegrass was, average, by 15.5% and 34.7% higher than the data featuring mechanical treatment. For Wod index those differences amounted 18.8% and 9.7% respectively.

Badania realizowano w latach 2002–2004 w Rolniczym Zakładzie Doświadczalnym „Swojec”, należącym do Uniwersytetu Przyrodniczego we Wrocławiu, w oparciu o dwuczynnikowe doświadczenie polowe. Czynnikiem I rzędu było nawożenie organiczne: międzyplon ścierniskowy uprawiany po uprzednio przyoranej słomie przedplonowej oraz bez słomy. Czynnikiem II rzędu była uprawa jesienno-wiosenna oraz nawożenie obornikiem; na trzech obiektach wykonano orkę przedzimową, na obiekcie 4 zastosowano orkę wiosenną, a na 5 uprawę konserwującą (międzyplon ścierniskowy pozostawiono do wiosny, przed siewem zastosowano bronę wirnikową). Nawożenie obornikiem zastosowano w wariancie 1 i 2 w dawkach odpowiednio 20 i 10 t·ha-1. Nawożenie buraka cukrowego biomasą międzyplonu ścierniskowego uprawianego po przyoranej słomie, w porównaniu z nawożeniem samym międzyplonem, na ogół przyczyniało się do poprawy zasobności gleby w makroelementy. Zmniejszenie dawki obornika z 20 do 10 t·ha-1 nie wywołało istotnego spadku zawartości podstawowych składników mineralnych. W przypadku braku nawożenia naturalnego zastosowanie uprawy konserwującej korzystniej wpłynęło na zasobność gleby niż systemy wykorzystujące orkę.

SummaryNowadays, when sustainable agriculture has become meaningful, legume crops, which provide high protein content feed and improve soil properties are of special value. A well-balanced cereal-legume mixtures brings many profits, such as better productivity or ecological benefits as improvement of cereal healthiness. In the aspect of the crop structure in Poland dominated by cereals this issue seems to be of a great importance. The aim of the experiment was to determine the health condition of spring triticale in cereallegume mixtures with diversified share of both components. Spring triticale cultivar Milkaro was sown with two cultivars of yellow lupine -Dukat and Mister. Pure sowing of triticale was compared with 50, 73, 86 and 94 share of triticale in mixture. A positive influence of legume participation in mixtures on spring triticale healthiness was shown. No significant influence on the tested properties of yellow lupine cultivars was stated.Key words: spring triticale; cereal-legume mixtures; healthiness StreszczenieW dobie rolnictwa zrównoważonego szczególnego znaczenia nabiera uprawa roślin strączkowych, które oprócz dostarczania wysokobiałkowej paszy, poprawiają właściwości gleby. Odpowiednio dobrana mieszanka zbożowo-strączkowa może oprócz efektów produkcyjnych przynieść znaczne korzyści ekologiczne, chociażby poprawę zdrowotności roślin zbożowych. Jest to ważne, gdyż od kilku lat udział zbóż w strukturze zasiewów w Polsce stanowi około trzy czwarte całkowitej powierzchni upraw. Celem badań było określenie zdrowotności pszenżyta jarego w mieszankach zbożowo-strączkowych z różnym udziałem obu komponentów. Pszenżyto jare odmiany Milkaro wysiewano z dwoma odmianami łubinu żółtego: Dukat i Mister. Stosowano siew czysty pszenżyta oraz mieszany z 50, 73, 86 i 94% udziałem pszenżyta. Wykazano korzystne oddziaływanie udziału rośliny strączkowej w mieszance z pszenżytem jarym na jego zdrowotność. Nie wykazano natomiast istotnego wpływu na badane cechy odmiany łubinu żółtego.