Ograniczanie wyników

Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 51

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 3 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  drip irrigation
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 3 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
2
100%
Drip irrigation system will play in the future a signifi cant role in fulfi lling the requirements of intensive, energysaving agricultural production. Total area under microirrigation in Poland can be now estimated as about 10 000 hectares. Drip irrigation is applied mainly in orchards, vegetable farms and greenhouses. The investigations on drip irrigation have shown a high infl uence of the agricultural conditions on the operation and reliability and productivity effects of the irrigation system. Paper present the investigation of the operation of drip irrigation systems in various regions of Poland. The analysis is based on the results of the manufacture coeffi cient of variation Cv, emitter exponent n, uniformity coeffi cient and detailed observation of the work time, breaks, failures and any other damages to the system.
In the climatic conditions of Poland the temporary lack of rainfall during the vegetation season, influenced on the water deficits in the top soil level. This situation can effect on the height and quality of yields in particular years. There is estimated that in the – so called – Large Valleys Region the water deficiency ranged 200-300 mm. Production of cucurbit’s vegetables in open field is strictly connected with thermal-rainfall conditions during the vegetation season. The optimal soil moisture is the very important factor for high and good quality yield. So, the production of the cucurbit plants should be connected with the irrigation installations. The aim of the study was to determine the influence of drip irrigation in cultivation of summer squash ‘Danka’ under light soil conditions. The trials were conducted in the years 2004 – 2006 at the experimental field in Kruszyn Krajeński near Bydgoszcz – on a soil of rye weak complex. The plot area for harvest was 9,1 m2. The irrigation rates were done on the base of soil water potential according to tensiometer indications. The irrigation was started when the soil water tension was – 0,04 MPa. The fruits of the summer squash were harvested in the technological maturity in the second decade of September in each year of the study. The single weight and number of the fruits as well as marketable yield from the unit area were estimated. In the pulp the dry matter, vitamin C, sugars and carotenoids content were determineted. It was found that drip irrigation significantly increased the marketable yield of fruits. The higher yield increases were detected in the years with lower rainfalls. The significant influence of drip irrigation on the content of vitamin C and sugars was stated. The dry matter and carotenoids content were higher in the fruits from the irrigated plots, but the difference was insignificant.
W pracy przedstawiono model matematyczny nawodnień kroplowych oraz wyniki dotyczące rozkładu uwilgotnienia gleby, wykorzystując własny program komputerowy. Stwierdzono, że stosowanie większej ilości emiterów kroplujących dla jednej rośliny (np. 4) ogranicza znacznie grawitacyjny odpływ wody poza strefę korzeniową.
On the basis of the field experiment carried out at the Experimental Station at Jadwisin (52°29’ N; 21°03’ E), Polish mid-early potato cultivar Triada was grown on sandy loam in years 2004 and 2005 in 6 treatments, which included the application of water and nitrogen: organic (cattle manure) and mineral. Water drip irrigation and nitrogen fertigation were scheduled by the Decision Support System (DSS). Diverse water supplies and organic or mineral nitrogen did not change harvest index (HI) values, which varied between 0.7 and 0.8 at the end of the growing period. Average tuber dry matter yield, about 11.0 t∙ha⁻¹, in both years of the investigation was reached with different HI values: 0.78 for 2004, and 0.73 for 2005. Higher percentage of biomass distributed to tubers was found in 2004, which was characterized by lower cumulative thermal time and global radiation, as well as better water balance in comparison with the growing period of 2005.
The aim of the present research was to compare the communities of oribatid mites (Oribatida) on the plantations of chokeberry (Aronia melanocarpa (Michx.) Elliott) and blackcurrant (Ribes nigrum L.) as well as to define the effect of microirrigation on those Acari. The experiment was performed in degraded Phaeozems formed from sand, on shallow-deposited sand in Kruszyn Krajeński in the vicinity of Bydgoszcz. The soil reaction was slightly acid or acid and the differences in the acidity between chokeberry and blackcurrant were inconsiderable. The abundance of oribatid mites on chokeberry and blackcurrant plantations ranged from 3110 to 5290 individuals · m-2 and it was much higher, as compared with the neighbouring set-aside. The density of Oribatida on blackcurrant plantation was clearly higher than in chokeberry; however there was recorded no significant effect of the type of irrigation on the density. In total on both plantations there were reported 31 species of oribatid mites; mean species number s in blackcurrant was higher than in chokeberry. The dominance structure of oribatid mites on the chokeberry plantation was more even than in blackcurrant and in Tectocepheus velatus communities dominated mostly. The species preferred the blackcurrant plantation and irrigation stimulated its abundance. Chamobates schutzii, an oribatid mite, came second; it preferred the soil of chokeberry plantation; it was especially numerous on irrigated stands. Scutovertex sculptus also demonstrated some preference for chokeberry soil and no tolerance to irrigation. Whereas such oribatid mite species as Gymnodamaeus bicostatus, Metabelba pulverulenta, Oppiella nova, Quadroppia quadricarinata and Damaeus sp. showed some preference for the blackcurrant plantation.
In the years 2005–2007, research work on the influence of surface and subsurface drip irrigation on the yield and quality of roots of parsley grown on ridges and on flat ground was carried out. Irrigation water was supplied via drip lines, which in subsurface irrigation were placed at a depth of 50 mm below the surface of the ridges, along the centreline between two rows of plants. In the case of surface irrigation, the drip lines were placed on the surface of the ridges between two rows of plants. Irrigation started when soil water potential was between -30 and -40 kPa. Nitrogen fertilizers (100 kg⋅ha-1) were applied in two doses. The first dose was applied pre-plant, while the second one was delivered by fertigation. In the control treatment without irrigation, the second dose of nitrogen was applied by broadcasting. Both surface and subsurface irrigation used in the cultivation on ridges and on flat ground had a significant effect on the marketable yield of parsley roots. However, no significant differences in the yield between surface and subsurface drip irrigation were found. The yield of non-marketable parsley roots in flat cultivation was twice as high as that in ridge cultivation. Parsley plants cultivated on ridges produced significantly longer, better-shaped storage roots compared to those cultivated on flat ground. Surface and subsurface drip irrigation significantly decreased the total N and K content in parsley roots.
The climate of Poland is characterized by a high variability, especially regarding the sum of precipitation and its distribution in the season. Dry years occur periodically. Repeated negative climatic water balance for vegetative season is insufficient for proper growth and development of plants. In this experiment we studied the effectiveness of drip irrigation in plum tree cultivation. The study was carried out since 1990 to 1998 in the orchard of the Institute of Pomology and Floriculture in Skierniewice. Trees of plum cv. Valor, grafted on Myrobalan and Wangenheim Prune seedlings were planted in the spring 1990 at a distance 4,2 m x 2,9 m. Influence of drip irrigation on trees growth changes, yield and fruit quality depended on weather conditions in the individual years. Generally, drip irrigation significantly increased the tree growth, yield and fruit quality. Higher positive effect of irrigation was obtained for plums grafted on Wangenheim Prune seedlings than on Myrobalan seedlings. Drought conditions clearly decreases the average weight of the fruit of the trees grafted on Wangenheim Prune. The rootstocks had no effect on fruit size.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 3 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.