Browsing by Subject "yield"

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  • Islam, Md. Safiqul (Helsingfors universitet, 2016)
    Mulching, as a cultivation technique, has been adopted since the early twentieth century in agriculture for improving various aspects of crop production. However, the use of mulching was boosted by the introduction of plastic mulch, which has been reported as a harmful substance to the farm environment. Therefore, the need for an environmentally benign mulch material is obvious. The present study investigated the effects of paper and biodegradable plastic mulches on the cucumber yield, soil temperature and moisture content (at 10 cm depth), and the control of weed growth in an agricultural field located at the University of Helsinki in Southern Finland. The degradability of mulches was also investigated. The null hypothesis was that all the mulches would have a similar effect on the abovementioned aspects. Four paper mulches, i.e., BP, KB, CK, and OB, accompanied by biodegradable mulch (BIO) and a bare soil (BG) treatment were under investigation. Each of these treatments had 4 replicates, and a randomized complete block design (RCBD) was adopted. Sensors were installed at 10 cm depth in each study plot to measure the soil temperature and moisture content. In addition, the experimental plots were watered by drip irrigation. All the attained data were analyzed using SPSS statistical software. The results of the study revealed noteworthy positive effects (P<0.05) of mulch application on cucumber yields together with soil temperature, early fruiting, and weed growth regulation compared to the un-mulched bare ground, exclusive of soil moisture content. The daytime soil temperature (DST) was higher than at night (NST), indicating a positive association of the mulch effect with plant growth and crop earliness. However, no suggestive improvement in soil moisture was found through mulch application during the study period. Edge degradation was only found for paper mulches during the study period, suggesting their environment friendliness. The CK and KB papers were the most effective and most environmentally positive mulch materials, and could be a suitable choice for Finnish vegetable growers. The findings of this study could assist paper manufacturers in improving the qualities of mulch papers regarding vegetable production. Future research aims at assessing the effects of mulches on the physiology of plants studied under mulched techniques together with the development of cheaper and more environmentally benign mulch materials.
  • Haapala, Tapani; Palonen, Pauliina; Tamminen, Antti; Ahokas, Jukka (2015)
  • Skovbjerg, Cathrine Kiel; Knudsen, Jens Nørgaard; Füchtbauer, Winnie; Stougaard, Jens; Stoddard, Frederick L.; Janss, Luc; Andersen, Stig Uggerhøj (2020)
    Abstract Faba bean is a legume crop with high protein content and considerable potential for wider cultivation in cool climates. However, it has a reputation for having unstable yield with large interannual variability, mostly attributed to yearly variation in rainfall. In this study, 17 commercial cultivars of faba bean were evaluated for seed yield, yield stability and the relationship between seed yield and protein content at four locations in Denmark and Finland during 2016?2018. We found that location and year effects accounted for 89% of the total seed yield variation. Cultivar ? environment (GxE) interactions were small (2.4%) and did not cause reranking of cultivars across environments. Yield stability contributed little to the mean yield of the cultivars, as high-yielding cultivars consistently outperformed the lower yielding genotypes, even under the most adverse conditions. Similarly, GxE effects on protein content were limited, and we found an overall negative correlation of ?0.61 between seed yield and protein content for the cultivars and environments studied. These data may be helpful for selecting cultivars for field use or for use in breeding programmes, considering that future faba bean pricing could depend on both protein quantity and concentration.
  • Peltonen-Sainio, Pirjo; Jauhiainen, Lauri; Känkänen, Hannu; Joona, Juuso; Hydén, Tony; Mattila, Tuomas J. (MDPI AG, 2022)
  • Haapala, Tapani; Palonen, Pauliina; Korpela, Antti; Ahokas, Jukka (2014)
  • Räfså, Tomas (Helsingfors universitet, 2014)
    More than half of the agricultural land in Finland is cultivated with cereals, and on many farms, cereals are also grown in monoculture. Studies have shown that crop rotation can decrease the need of inputs and also increase crop yields. At the same time more knowledge is needed about qualities and benefits of different crops. The aim of this study was to investigate the qualities of white lupin as a one year green manure crop, and to investigate its impact and nitrogen effect on barley yield formation and yield quality during the subsequent growth period. The aim was furthermore to investigate if white lupin affected soil mineral nitrogen content. A two year long field experiment was established during the growth season of 2010 at Viikki research farm in Helsinki. In year 2010 white lupin, barley and fallow was cultivated as precrops for the following growth period. In year 2011 only barley was cultivated and different nitrogen treatments were included in the experiment to be able to evaluate precrop nitrogen effect. In year 2011 cultivation of white lupin and barley was also repeated in a second field experiment. In the experiments, white lupin lenght development, ground coverage and biomass accumulation were recorded and compared with barley. The total amount of nitrogen that white lupin accumulated was also determined. In year 2011 precrop and nitrogen treatment effects on barley yield formation and yield quality was determined. Precrop and nitrogen treatment effects on soil mineral nitrogen was investigated from fall 2010 to fall 2011. White lupin was successfully cultivated without any input of fertilizers. White lupin showed less ground coverage in early summer, and therefore showed inferior weed competition compared with barley. White lupin achieved the same plant lenght and total biomass as barley, but accumulated over 200 N kg/ha. In the precrop and nitrogen treatments, barley grain yield did not indicate any need of nitrogen fertilizer, where white lupin had been used as precrop. Grain protein content, however, showed that even with white lupin as precrop, a 20 kg/ha nitrogen starter was not sufficient. Soil mineral nitrogen content was clearly increased by white lupin only before sowing in year 2011.
  • Mustonen, Arja; Termonen, Maarit; Kykkänen, Sanna; Järvenranta, Kirsi; Yli-Halla, Markku; Virkajärvi, Perttu (European Grassland Federation, 2022)
    Grassland Science in Europe,
  • Nogalska, Anna; Chen, Lin; Sienkiewicz, Stanislaw; Nogalski, Zenon (2014)
  • Haarlaa, Rihko (Suomen metsätieteellinen seura, 1973)
  • Kukkola, Annukka (Helsingin yliopisto, 2022)
    Biochars are produced from organic materials using pyrolysis and are used as a soil amendment to improve soil fertility and plant growth. Biochars are particularly beneficial to soils with high acidity, low carbon (C) content, nitrogen (N) content and other nutrient contents. However, it is not well-studied whether the beneficial effects of a biochar exist for the long-term. The aim of this study was to examine the effects of one-time application of spruce biochar on soil and barley (Hordeum vulgare L.) properties in the long-term. For this purpose, soil and plant properties were measured from the biochar field experiment in a boreal nutrient deficient Umbrisol where spruce biochar was applied eight years earlier. The experiment had a split-plot design with biochar application rates (0, 5, 10, 20 and 30 t ha-1) as the main-plot factor. The effects of fertilisers alone and their interaction with biochar were studied with three treatments (control, mineral fertiliser and meat bone meal (MBM)) as the sub-plot factor. Soil moisture content at 0–15 cm depth, as well as pH, plant available nutrients, total C and N content and C/N ratio of the soil were measured. Barley growth was assessed indirectly by measuring leaf chlorophyll content (SPAD), leaf area index (LAI), plant stand density, biomass, C and N content, C/N ratio, grain yield and weight of 1000 grains (TGW). No consistent significant effects of biochar on soil moisture content or soil chemical properties were observed. Biochar application did not have significant effects on leaf chlorophyll, leaf area index, plant density or biomass of barley. The highest biochar application rate of 30 t ha-1 tended to increase grain yield and TGW but the increases were not statistically significant. Mineral and MBM fertilisers produced similar grain yields although N was likely less available from MBM earlier in the growing season. Biochar and fertiliser interaction did not have significant effects on any of the measured properties. The lack of effects of biochar may be explained by the high amount of initial soil organic matter as well as low liming effect and low nutrient content of the used biochar. In addition, the lack of significant effects of biochar also suggests loss of biochar from topsoil due to weathering and downward displacement of biochar over the period of eight years. In this study, biochar application did not have negative consequences on the measured soil and crop properties. Therefore, it should be safe to use. Biochars may provide a viable option to sequester carbon in boreal agriculture. Further research on this is still needed to investigate the long-term effects of different types of biochars on different types of soils.
  • Pinomaa, Anni (Helsingfors universitet, 2016)
    Protected cultivation of raspberries (Rubus idaeus L.) has increased its popularity in Finland. One reason is that the fruit is extremely sensitive to rainy weather during its development. The raspberry plant itself is sensitive to wind and low temperatures, which can reduce growth. In Europe most of the raspberry is grown in protected cultivation, and this technology is now becoming popular in Finland. A high tunnel is a cost-efficient way to protect the plants against rainy weather and extend the harvest season. The protected cultivation has been shown to increase the yield and cropping potential of raspberry and reduce the gray mold in the berries. In human diet, berries are among the richest sources of antioxidants. In raspberry, the most important antioxidants are vitamin C (20 %) and phenolic compounds (80 %). Among phenolic compounds, ellagitannins and anthocyanins give the greatest contribution to antioxidant activity. The aim of this thesis was to study the yield, sensory quality, nutritional quality and shelf life of three floricane fruiting raspberry cultivars grown in high tunnel and open field. Cultivars ’Glen Ample, ’Glen Dee’ and ’Maurin Makea’ were used in the study. Sugar and acid content of raspberry were examined to get an overview of sensory quality. The nutritional quality was studied with an antioxidant activity assay (using FRAP method) and total phenolics assay (using Fast Blue BB method). The shelf life was tested both in +5 °C and in room temperature. The average total yield per cane was 99 % greater in tunnel than in the open field, whereas both sugar and acid content of the berry were greater in open field. Berry weight and total phenolics content were strongly cultivar dependent characteristics. The results of the antioxidant activity assay did not show significant differences between either growing conditions or the cultivars. The shelf life in room temperature was equally weak for all samples, but in +5 °C storage the open field raspberries developed symptoms of gray mold earlier than those picked from the tunnel. The conclusion is that contents of health beneficial compounds in berries were not affected in tunnel cultivation, but berry taste may be affected, as differences in sugar and acid contents were observed.
  • Huuki, Hannu; Karhinen, Santtu; Böök, Herman; Lindfors, Anders V.; Kopsakangas-Savolainen, Maria; Svento, Rauli (Elsevier, 2020)
    Journal of Energy Storage 28 (2020), 101202
    Intermittent renewable energy generation, which is determined by weather conditions, is increasing in power markets. The efficient integration of these energy sources calls for flexible participants in smart power grids. It has been acknowledged that a large, underutilized, flexible resource lies on the consumer side of electricity generation. Despite the recently increasing interest in demand flexibility, there is a gap in the literature concerning the incentives for consumers to offer their flexible energy to power markets. In this paper, we examine a virtual power plant concept, which simultaneously optimizes the response of controllable electric hot water heaters to solar power forecast error imbalances. Uncertainty is included in the optimization in terms of solar power day-ahead forecast errors and balancing power market conditions. We show that including solar power imbalance minimization in the target function changes the optimal hot water heating profile such that more electricity is used during the daytime. The virtual power plant operation decreases solar power imbalances by 5–10% and benefits the participating households by 4.0–7.5 € in extra savings annually. The results of this study indicate that with the number of participating households, while total profits increase, marginal revenues decrease.