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Research focusing on the nitrogen (N) application and N use of forage maize (Zea mays L.) in the boreal region is either limited or non-existent. The aim of this study was to investigate the response of yield, quality and N recovery efficiency (NRE) of forage maize to an increase in the N application rate and different climatic conditions in two locations in Finland. The field experiment was conducted in southern (Helsinki; 60° N) and central (Maaninka; 63° N) Finland in 2019 and 2020. Dry matter (DM) yield, forage quality and NRE were determined for N application rates of 100, 150 and 200 N kg ha−1. The DM yield was similar to all studied N application rates. Moreover, there were no marked differences in the studied forage quality traits or the NRE following the N application rates. However, the NRE of maize was generally low at 45%. The current study recommends a N application rate of 100–150 N kg ha−1 for forage maize in the boreal region. There is no need to increase the N application from current recommendations since climate conditions seem to limit the growth, development and NRE of forage maize. The observed low NRE of forage maize warrants further research in the future.

Correction INDUSTRIAL CROPS AND PRODUCTS Volume187 PartA Article Number115417 DOI10.1016/j.indcrop.2022.115417 PublishedNOV 1 2022 Caraway seeds contain between 0.5-7% essential oil, rich in monoterpenes that have a characteristic aroma and chemical properties. Caraway oil has several bioactive compounds that are of industrial importance, particularly for pharmaceutical and health care products. Carvone and limonene are the main terpenes present in caraway oil, which along with some unique fatty acids (i.e. petroselinic acid) determine caraway (Carum carvi L.) oil quality. Both terpenes are important raw materials for industrial applications and their concentration influences the price of caraway seed and oil, hence there is need for identifying management practices that may increase the concentration of these and other bioactive compounds to improve caraway seed oil quality. A field experiment with five treatments: a control and a series of foliar-applied micronutrients (either Cu, Mg, Mn or Zn was done to identify their potential to enhance caraway oil quality. Solid-phase microextraction and gas chromatography with a flame ionization detector were used to characterize oil quality. Our results indicate that while the micronutrient treatments have a significant effect on essential oil composition, both in carvone and limonene, such an effect was not found on all fatty acids but only in two of them-palmitoleic and vaccenic acid-, which were highest after the Mn treatment. Overall, the carvone content of the seeds decreased the least between years following Mn treatment. Mn treatment also caused an increase in limonene in the second year in contrast to the trend for all other treatments. The Mn foliar spray needs to be studied further to elucidate whether it could have a consistent positive effect on caraway oil seed quality upon adjusting dosage and spraying time.

Difficulties in efficient utilization of seasonal precipitation cause limitations in yields and even total crop failure on rainfed farms in semi-arid East Africa. The objective of the present study was to find out if covering the soil with plant residue mulch at a semi-arid site could retain water in the soil between precipitation events and build dry spell resilience by reducing soil water evaporation and increasing infiltration to deeper soil. Covering soil with plant residue mulch was studied at a smallholder farm in semi-arid Kenya by continuously measuring volumetric soil moisture content with soil sensors at multiple depths in bare soil and in maize (Zea mays L.) plant residue mulched soil. A physically based one-dimensional soil moisture model was calibrated and used to estimate the effect of plant residue mulch on soil moisture over a two-year period (multiple growing seasons). The modelled multiyear time series provides an estimate of the effect residue mulches of different thicknesses have on soil moisture over time. The simple soil moisture model was able to estimate soil moisture in the effective root zone of maize. By comparing measured data from mulched and uncovered soil and by model prediction, it was demonstrated that maize residue mulch conserved soil moisture over time in the effective root zone of maize compared to bare soil. During the two-year period mulching increased the total amount of days when measured relative soil moisture (s) exceeded water stress limit of maize (s*) by 24%-46%. Moisture accumulated in the mulched profile, especially in the deeper layers of the effective root zone. Calculations indicated that further increasing mulch thickness (delta(m)) from 1 to 3 cm would have increased the total days when s > s* 59%. Furthermore, increasing delta(m) from 3 to 5 cm would have resulted in 25% increase in total days when s > s*. According to our calculations mulching (delta(m) > 1 cm) could have maintained s > s* throughout a 19 days dry spell that occurred during the measurement period. The demonstrated moisture conserving effect of mulch increases with delta(m), but availability of plant residue may set limits on mulch application rates. The results suggest that maize residue mulching is as an accessible and feasible method for conserving soil moisture in the effective root zone in dryland smallholder systems in East Africa.

Water deficit limits cassava (Manihot esculenta Crantz) productivity in drought-prone areas and alters the nutritive quality of the crop. Potassium (K) may mitigate the effects of water deficit and improve the nutritional content of cassava, which would alleviate malnutrition among the human population in the tropics who depend on cassava as a staple food. Pot experiments were conducted under controlled glasshouse conditions to investigate the influence of deficit irrigation and K fertigation on the nutritive and anti-nutritive quality of biofortified cassava during the early growth phase. Treatments initiated at 30 days after planting were three irrigation doses (30, 60, 100% pot capacity) that were split to five K (0.01, 1, 4, 16, and 32 mM) concentrations. Plants were harvested at 90 days after planting, and the starch, energy, carotenoid, crude protein, fiber, minerals, and cyanide concentration of the leaves and roots were determined. Irrigation and K treatments showed significant (P

Mixed cropping, including intercropping, is the oldest form of systemized agricultural production and involves the growing of two or more species or cultivars of the same species simultaneously in the same field. However, mixed cropping has been little by little replaced by sole crop systems, especially in developed countries. Some of the advantages of mixed cropping are, for example, resource use efficiency and yield stability, but there are also several challenges, such as weed management and competition. The boreal-nemoral region lies within the region 55° to 70° N. In this area, for example in Finland, the length of the thermal growing season varies from less than 105 to over 185 days. Typically, variation between locations and years is marked. However, during the year, there can be a wide range of temperature extremes between −70 and +30 °C. The majority of cropping systems in this region are usually monocultures, except for forage grass mixtures. The possibility of having several crops in a mixture is very challenging in the region due to the short growing season and extreme cold temperatures, meaning that crop earliness and overwintering capacity are a considerable restriction for year-round mixed cropping. A further restriction is the quality requirements set by the industry. Our review will explore a range of mixed cropping possibilities for the boreal-nemoral region, including different possible combinations of spring, winter, perennial, biennial, catch, and cover crops. The reviewed mixed cropping systems could considerably improve the sustainability and efficiency of crop production, particularly with an emphasis on nutrient cycling.

Phosphorus (P) is an essential element for plant growth and development. Finding new P sources and ways to improve crop P utilization are necessary due to the depletion of phosphate reserves. Five crop species, buckwheat (Fagopyrum esculentum L.), maize (Zea mays L.), oilseed rape (Brassica napus L. ssp. oleifera (Moench) Metzg.), spelt wheat (Triticum spelta L.), and white lupine (Lupinus albus L.), were grown in pots containing sandy soil with chemical nutrients, digestate, and meat bone meal (MBM) without added nutrients. Thirty days after the seeding plants were harvested, the growth stage, soil-plant analysis development (SPAD) value, biomass, P content of the plants, colonization of the roots with endomycorrhiza, and soil pH were analyzed, and the number of fungal spores in the soil was counted. All species showed interaction with the P sources for measured traits, except for the rhizosphere pH. A high biomass was recorded in all species fertilized with various P sources compared to the unfertilized treatment. Buckwheat and spelt wheat showed a higher P uptake with MBM, and the mycorrhizal symbiosis improved with digestate or MBM compared to synthetic P. The results indicate that different species have adaptative mechanisms to various P sources which could improve the resilience and sustainability of cropping systems.

Cassava (Manihot esculenta Crantz) experiences intermittent water deficit and suffers from potassium (K) deficiency that seriously constrains its yield in the tropics. Currently, the interaction effect between deficit irrigation and K fertigation on growth and yield of cassava is unknown, especially during the early growth phase. Therefore, pot experiments were conducted under controlled greenhouse conditions using cassava cuttings. Treatments initiated at 30 days after planting included three irrigation doses (30%, 60%, 100% pot capacity) and five K (0.01, 1, 4, 16, and 32 mM) concentrations. The plants were harvested 90 days after planting. Decreasing irrigation dose to 30% together with 16 mM K lowered the leaf water potential by 69%, leaf osmotic potential by 41%, photosynthesis by 35%, stomatal conductance by 41%, water usage by 50%, leaf area by 17%, and whole-plant dry mass by 41%, compared with full-irrigated plants. Lowering the K concentration below 16 mM reduced the values further. Notably, growth and yield were decreased the least compared with optimal, when irrigation dose was decreased to 60% together with 16 mM K. The results demonstrate that deficit irrigation strategies could be utilized to develop management practices to improve cassava productivity by means of K fertigation under low moisture conditions.

Leafy vegetables like lettuce (Lactuca sativa L.) naturally have high nitrate content and the European Commission has set maximum level for nitrate in lettuce. Glycinebetaine is an organic osmolyte alleviating plant stress, but its role in leaf nitrate accumulation remains unknown. The uptake of glycinebetaine by lettuce roots, and its potential to regulate lettuce nitrate content and improve plant quality were investigated. Two hydroponic lettuce experiments were conducted with different glycinebetaine application rates (Exp1 : 0, 1, 7.5, and 15 mM; Exp2: 0, 1 + 1 + 1, 1 + 10, and 4 mM). Plants were analyzed at varying time points. Root application resulted in glycinebetaine uptake and translocation to the leaves. Glycinebetaine concentrations > 7.5 mM reduced leaf nitrate up to 40% and increased leaf dry matter content. Glycinebetaine showed a positive effect on leaf mineral and amino acid composition. Thus, glycinebetaine could be a novel strategy to reduce the nitrate content in hydroponic lettuce.

Studies of plant adaptation to saline or dry environments have for several years recognized the role of quaternary ammonium and tertiary sulfonium compounds as nontoxic compatible solutes. One of the most studied compounds is glycinebetaine (GB), earlier known as lycine or oxyneurine. GB is a nontoxic, odorless, tasteless, and colorless amino acid derivative. Several plant species accumulate GB naturally as a response to abiotic stresses. However, many crop species are not able to synthesize GB in physiologically meaningful concentrations. On the other hand, halophytes, plants that can tolerate a high concentration of salt in the soil, are known to synthesize GB in low concentrations even when they are not experiencing any stress. GB is synthesized in chloroplasts from choline via a two-step oxidation reaction. This synthesis pathway has been the target in many attempts to either introduce or increase GB synthesis in plants by a transgenesis approach. However, in many cases the availability of choline obtained through photorespiration has restricted GB synthesis. Furthermore, availability of nitrogen can also restrict GB synthesis, since GB contains approximately 12% nitrogen. GB has so far been considered a relatively inert compound in plants. Since GB does not interact with metabolic pathways in the plant, it remains available at the cellular level for its use. Thus, it can be hypothesized that plants could be able to utilize nitrogen through GB metabolism, for example, during stress recovery. On the other hand, GB synthesis is energetically expensive for plants. Synthesis of 1 GB mole costs approximately 50 ATP moles, whereas synthesis of 1 sucrose mole costs approximately 30 ATP moles. In comparison, osmotic adjustment with inorganic ions is less costly, e.g., 1 NaCl mole equals 3.5 ATP moles. The aim of this chapter is to provide an overview of endogenous GB in plants and the transgenesis approach for introducing and improving GB synthesis in plants.

Background Digested sludge is a good source of plant nutrients. However, depending on the feedstock, it might contain heavy metals, metalloids, organic compounds, pathogens, and pharmaceuticals, which can cause adverse effects on crop growth and contaminate the groundwater, soil, and food chain. Scope The aim of this review is to focus on the potential risks of inorganic and organic contaminants to plant growth, soil, groundwater, and consequently the food chain and environment related to the utilization of digested sludge as a fertilizer on cropland. Conclusions Inorganic compounds, such as metals and metalloids, in sludge can occasionally cause reductions in soil microbial biomass. In general, the uptake of metals and organic contaminants does not appear to cause a significant hazard to the plants and the concentrations do not surpass the maximum values allowed in soil. Organic compounds, harmful for human health or the environment, are to a large extent decomposed or volatilized from the land treated with sludge, which decreases their leaching into the environment. Many of the organic compounds are lipophilic and can be bound to soil organic matter. In conclusion, the application of sludge on cropland might be a sustainable management practice; however, further investigations are needed to determine the accumulation and persistence of possible hazardous emerging chemicals and pathogens in the environment and formation of harmful intermediate reaction of inorganic and organic compound products.

Jerusalem artichoke (Helianthus tuberosus L.) produces substantial shoots not used as food. To test its potential as a sustainable bioenergy crop, we studied the effects of synthetic fertilizer and intercropped legumes as nitrogen (N) sources on the growth, aboveground biomass dry matter yield and energy qualities of this crop. Plant height, leaf area index (LAI), SPAD-value, biomass yield, ash content and mineral element composition were determined. Mean aboveground biomass yields were not significantly affected by N source (legume intercrops and synthetic fertilizer) and ranged from 13 to 17 t ha(-1). Remarkably, plants given no fertilizer yielded equally to plants given 90 N kg ha(-1). These results confirm that Jerusalem artichoke, compared to other energy crops, have less need for N and can potentially be sustained by N fixing legumes in an intercropped system. This could reduce or eliminate production and environmental cost in cultivation of biomass feedstock for energy use.

Leaf area index (LAI) is an important biophysical variable for understanding the radiation use efficiency of field crops and their potential yield. On a large scale, LAI can be estimated with the help of imaging spectroscopy. However, recent studies have revealed that the leaf angle greatly affects the spectral reflectance of the canopy and hence imaging spectroscopy data. To investigate the effects of the leaf angle on LAI-sensitive narrowband vegetation indices, we used both empirical measurements from field crops and model-simulated data generated by the PROSAIL canopy reflectance model. We found the relationship between vegetation indices and LAI to be notably affected, especially when the leaf mean tilt angle (MTA) exceeded 70 degrees. Of the indices used in the study, the modified soil-adjusted vegetation index (MSAVI) was most strongly affected by leaf angles, while the blue normalized difference vegetation index (BNDVI), the green normalized difference vegetation index (GNDVI), the modified simple ratio using the wavelength of 705 nm (MSR705), the normalized difference vegetation index (NDVI), and the soil-adjusted vegetation index (SAVI) were only affected for sparse canopies (LAI &lt, 3) and MTA exceeding 60&deg, Generally, the effect of MTA on the vegetation indices increased as a function of decreasing LAI. The leaf chlorophyll content did not affect the relationship between BNDVI, MSAVI, NDVI, and LAI, while the green atmospherically resistant index (GARI), GNDVI, and MSR705 were the most strongly affected indices. While the relationship between SR and LAI was somewhat affected by both MTA and the leaf chlorophyll content, the simple ratio (SR) displayed only slight saturation with LAI, regardless of MTA and the chlorophyll content. The best index found in the study for LAI estimation was BNDVI, although it performed robustly only for LAI &gt, 3 and showed considerable nonlinearity. Thus, none of the studied indices were well suited for across-species LAI estimation: information on the leaf angle would be required for remote LAI measurement, especially at low LAI values. Nevertheless, narrowband indices can be used to monitor the LAI of crops with a constant leaf angle distribution.

Work life relevance is emphasized these days in higher education. In addition to domain-specific knowledge and skills, students should learn general work life competencies, such as team work, networking, project work and digital skills. At the University of Helsinki, agricultural science students’ work life skills are promoted in a project course. The 5 ETCS course has been held for B.Sc. and M.Sc. students in 2016 and 2017. The course in 2016 had eight students and three supervisors in two project teams; the course in 2017 had 15 students in four teams, and six supervisors (university teachers). Each team had its own external client from businesses and national government departments. The course implementation was examined from a design-based research approach. The aim of the study was to evaluate the summative evaluations made by all groups participating in the course, receive research-based knowledge about improving the course design further, and to try out instruments and methods that can be used in educational practice to assess participant satisfaction and competence development during courses about work life. An online questionnaire was used to examine the evaluations of the supervisors and students about the success of the course and the competencies gained by the students (Collaborative Knowledge Practices Questionnaire, CKP). Interviews were used to examine the views of the clients concerning the realization and development of the course. The data were analysed using quantitative and qualitative methods. The project process was mostly graded the same by the evaluators (students, supervisors and clients), but most student groups gave the report a higher grade than the other evaluators did. Students’ evaluations were that they had acquired knowledge work competencies well, particularly the development of shared objects, the integration of individual and collaborative working and persistent development of knowledge objects. The students particularly appreciated team work for achieving common goals, development of project work and work life skills, interesting project topics and interaction with the customers. Challenges were the open assignments and related uncertainty of working methods, coordination of group work and students’ inadequate skills in relation to project work requirements. The tight schedule of 11 weeks in 2016 led to the course being extended to 16 weeks in 2017. All clients evaluated their participation in the course as being positive. They appreciated being able to help students to practice work life skills and the university to develop teaching. Collaboration was seen as a good way to create contacts with students from the viewpoint of future workplaces. Project work outcomes provided new information for the development of the client organizations or supplemented and strengthened earlier views. As targets for improvement, the clients mentioned better definition of appropriate assignments for student teams and the development of interaction practices, e.g. by organizing virtual meetings. For the supervisors, the motivated working of the students and finishing of the projects in time were positive aspects. It was challenging to define appropriate topics for the client assignments, requirements of the course in relation to the skills of the students and timing of the course as well as their own time management. All parties experienced work life-oriented project courses as necessary and rewarding for all parties. Research-based evaluation provided useful information for developing the course design further. Non

Allelochemicals of Brassica can inhibit a wide range of soil-borne pathogenic fungi. In the present study, the effects of different turnip rape ( Brassica rapa ) cultivation treatments on the soil fungal community were investigated in two experiments in 2009 2010 and 2010 2011. The treatments used turnip rape as a green manure, as a mixed-crop with barley, or as a rotational crop after barley, with continuous barley as the reference. The composition of the soil fungal community was monitored with capillary-based length heterogeneity PCR using primers ITS1F/ITS4. The operational taxonomic units (OTUs) identified as the pathogens Botrytis cinerea , Rhizoctonia solani and Sclerotinia sclerotiorum did not respond to different treatments. Fungal diversity was the lowest and the relative abundance of Fusarium spp. the highest in barley monoculture. Incorporation of turnip rape plants into the soil as green manure was associated with a low relative abundance of Fusarium spp. Turnip rape as a mixed crop or rotational crop did not substantially decrease the relative abundance of Fusarium spp. Aqueous and non-polar extracts of allelochemicals from turnip rape had very little effect on the growth of Fusarium culmorum in vitro . We conclude that high fungal diversity, resulting from either application of fertilizer or incorporation of organic matter of turnip rape, was more important than allelochemicals in affecting the growth of Fusarium spp. in field soils.

Winter turnip rape [Brassica rapa L. ssp. oleifera (DC.) Metzg.] is an oilseed crucifer mainly grown in Nordic and Baltic countries. It can be undersown in a spring cereal as an alternative to sowing of pure stand in late July. Establishment by undersowing helps to utilize the short growing season at high latitudes. However, as undersown crops tend to affect the growth and yield of their companion crops, the effect of undersown winter turnip rape on cereal yield and quality needs to be assessed. Additionally, an evaluation of the suitability of different cereals as companion crops to winter turnip rape is required before practical recommendations can be made. The suitability of four spring cereals as companion crops to winter turnip rape was studied in three field experiments. Two-row barley, six-row barley, wheat and oat were sown at two different densities, with and without undersown winter turnip rape, sowing density depending on the density of the cereal. Undersowing winter turnip rape in a cereal did not markedly affect cereal yield. In some years six-row barley and oat with undersown winter turnip rape produced more yield than corresponding pure stands, indicating a possible facilitative effect of the undersown crucifer on the two cereal species. The results suggest that the most compatible cereals as companion crops with undersown winter turnip rape are six-row barley and oat. Mixed stand cultivation could be improved trough the identification of the optimal cereal–winter turnip rape combinations.

The biomass potential of eight high yielding maize cultivars was studied in the sub-boreal climate of southern Finland. The effects of harvest date on lignin and sugar production, biomass yield, mineral element composition, bioenergy potential and soil nutrient management were determined in two years. The eight maize cultivars produced 17.6–33.3 t ha-1 of biomass. The ear fraction contained 50–60% of the biomass, and ash and mineral element composition of the plant fractions were significantly different (p < 0.001), with more ash, Ca and S in the above-ear fractions of the plants than in the mid-stalk portions, whereas the C:N ratio was highest in the lower stalk. Cultivars with less lignin content produced more fermetable sugars. Despite the relatively cool growing conditions and short season of the sub-boreal region, maize has potential for use as biomass, for biofuel or other uses. The crop can be fractioned into ear and stalk, with the lower 20 cm of stalk left in the field to maintain soil organic matter content.

Bioenergy cropping, like all agricultural practices, may lead to the release of greenhouse gases. This study was aimed at determining biomass and energy yields of reed canary grass (RCG) (Phalaris arundinacea), galega (Galega orientalis) and a mixture of these, and to relate these to fluxes of nitrous oxide (N2O), a potent greenhouse gas, emitted from the soils. Plots including a bare fallow as control were established in 2008. Gases emitted from the soil surface were collected in closed chambers from May 2011 to May 2013, except during periods of snow cover, and analysed by gas chromatography. Seasonal and annual cumulative emissions of N2O and CO2 equivalents per unit energy yield were calculated. Soil moisture content, nitrate (NO3 −)-N and ammonium (NH4 +)-N were also determined. Both species composition and crop yields affected energy yields and N2O emission from the soil. The annual cumulative emissions from mixture were marginally lower than those from fertilized RCG soils. Fertilized RCG produced twice as much biomass and correspondingly higher nitrogen and energy yields, so its low emission of N2O per Mg of dry matter was not significantly different from that of the mixtures. Cropping an RCG–galega mixture for biofuel may replace N fertilizer input since it resulted in lowering N2O fluxes, but requires management to maintain grass as the major component in order to minimize N2O emissions. In a time of climate change, low-input bioenergy crops may be a suitable strategy for land left uncropped after ploughing for one season or longer.

Reliable estimation of leaf chlorophyll-a and -b content (chl-a + b) at canopy scales is essential for monitoring vegetation productivity, physiological stress, and nutrient availability. To achieve this, narrow-band vegetation indices (VIs) derived from imaging spectroscopy data are commonly used. However, VIs are affected by canopy structures other than chl-a + b, such as leaf area index (LAI) and leaf mean tilt angle (MTA). In this study, we evaluated the performance of 58 VIs reported in the literature to be chl-a + b-sensitive against a unique measured set of species-specific leaf angles for six crop species in southern Finland. We created a large simulated canopy reflectance database (100,000 canopy configurations) using the physically based PROSAIL (coupling of PROSPECT and SAIL (Scattering by Arbitrarily Inclined Leaves) radiative transfer models) model. The performance of model-simulated indices was compared against airborne AISA Eagle II imaging spectroradiometer data and field-measured chl-a + b, LAI, and MTA values. In general, LAI had a positive effect on the strength of the correlation between chl-a + b and VIs while MTA had a negative effect in both measured and simulated data. Three indices (REIP (red edge inflection point), TCARI (transformed chlorophyll absorption ratio index)/OSAVI (optimized soil-adjusted vegetation index), and CTR6 (Carter indices)) showed strong correlations with chl-a + b and similar performance in model-simulated and measured data set. However, only two (TCARI/OSAVI and CTR6) were independent from LAI and MTA. We consider these two indices robust proxies of crop leaf chl-a + b.

Poor water retention capacity (WRC) and nutrient deficiency commonly limit crop yields in sandy soils. The use of biochar as a soil amendment has been previously reported to improve these limiting factors in subtropical and temperate soils. We studied the effects of biochar on soil properties and yield formation of spring wheat (Triticum aestivum L.) when applied together with inorganic fertiliser or meat bone meal (MBM) to an Endogleyic Umbrisol with a loamy sand texture in boreal conditions. In a two-year field experiment, biochar was applied at 0, 5, 10, 20 and 30 t ha−1 combined with three fertiliser treatments (unfertilised control, MBM and inorganic fertiliser) providing equal amounts of nitrogen (N), phosphorus (P) and potassium (K). Soil WRC and fertility as well as wheat yield, yield components and quality were analysed. Soil moisture content, leaf area index and leaf chlorophyll values (SPAD) were monitored during the experiment. Biochar increased the plant-available water content of the topsoil in the first year and reduced the bulk density in the second year after application. It also increased the contents of easily soluble K and soil organic C (SOC) in the 20 cm of topsoil, but had no effects on other soil nutrients, pH or moisture content. Biochar amendment decreased the soil NO3−-N content below control values in the first year but increased it significantly in the second year. The addition of biochar did not significantly affect the nitrogen uptake, grain yield or quality of wheat, possibly because of its low nutrient availability and the high organic matter content of the soil.

International audience; Leaching of nitrogen fertilizers such as nitrates from agricultural systems causes watershed eutrophication and is an economic loss for the farmer. This issue may be solved by including a catch crop in a crop rotation. For instance, winter turnip rape is a potential N catch crop for cold climates. Here, we studied winter turnip rape as a catch crop from 2009 to 2011 in Finland. Winter turnip rape was either undersown with barley in May or sown after harvesting barley in late July. In two reference treatments, the barley stubble was either left over the winter or ploughed into the soil in autumn. We collected samples from topsoil, 0-20 cm, and subsoil, 30-50 cm, in early autumn, before snowfall and in the following spring. We measured soil ammonium-N and nitrate-N, and the N content of winter turnip rape plants. Results show that undersown winter turnip rape did not change the yield and quality of barley. Winter turnip rape decreased nitrate-N in the subsoil by 83 % in 2009 and by 61 % in 2010, compared to ploughed barley. By the end of October 2009, winter turnip rape undersown in May took up 74 kg N/ha, whereas the crop sown after barley in July took up 57 kg N/ha. We conclude that winter turnip rape, either undersown with barley or sown after barley, is effective in depleting subsoil nitrates. Even though numerous reports describe the efficiency of different crucifers as catch crops under temperate climate, this is the first article concerning winter turnip rape as a catch crop under cold and humid climate.

(Received 6 June 2013; revised 22 November 2013; accepted 31 January 2014)SUMMARYCultivationofwinterturniprape(BrassicarapaL.ssp.oleifera(DC.)Metzg.)inFinlandhasbeenlimitedbecauseofits reputation as an unreliable crop and its mid-season sowing time of July, when fields are already sown to othercrops. An alternative management practice for winter turnip rape is proposed whereby it would be sown as amixed crop simultaneously with spring cereals. The growth and yield formation of winter turnip rape grown inmixed stands with four different spring cereals was studied in two field experiments conducted in 2009–11. Pureand mixed stands of winter turnip rape and spring cereals were established in May at two different cereal andwinter turnip rape stand densities. Subsequent to cereal harvest, one-third of each winter turnip rape plot washarvested for biomass in autumn, before cessation of growth. Three plant stand types, May- and July-sownmonocrops and a mixed crop with oat (Avena sativa L.) were sampled for forage analysis. Plant stand densitieswere monitored from establishment until maturity. Winter turnip rape yield and its quality, including oil content,protein content and thousand seed weight, were determined. Following favourable overwintering conditions,winter turnip rape established with cereals yielded comparably to that of pure stands in terms of both quantityand quality. However, a pure stand of winter turnip rape out-yielded mixed crop stands after unfavourableoverwintering conditions. Leaf removal decreased plant survival and seed yield. Establishing winter turnip rapewithacerealinMayisanalternativetosowingitasamonocropinJuly.Ahigherseedingrateisneededforunder-sown winter turnip rape. Furthermore, autumn-harvested winter turnip rape monocrop forage potentiallyrepresents a high-protein supplement for ruminants.INTRODUCTIONWinter turnip rape (Brassica rapa L. ssp. oleifera (DC.)Metzg.) is a cruciferous oilseed crop better adapted tothe Nordic climate than oilseed rape (Brassica napusL. ssp. oleifera (Moench) Metzg.). Because of its rapidgrowth, it out-competes weeds and consequentlysuitsorganic farming production systems (Makela et al.2011). Moreover, winter turnip rape can be harvestedbefore other crops because it reaches maturity earlierthanothercrops,i.e.inJuly,andsinceitisalsosowninJuly, it is in the ground for 12 months of the year. InFinland, winter turnip rape is sown by the end of Julybecause late sowing results in yield reduction (Valle1951). This is a limiting factor for winter turnip rapecultivationsincefarmsusuallyhavenofreelandatthattime because most field crops do not mature beforeAugust. A potential solution to this problem would beto sow winter turnip rape in May with a cereal andthereby reduce the costs of establishing the cropwhileincreasing land-use efficiency. The cereal would beharvested, as usual, in autumn and the winter turniprape would remain in the field to overwinter andproduce seed in the following growing season (Valle1951). Mixed crop stands often capture more mineralnutrients than pure stands (Midmore 1993; Morris &Garrity 1993a) and are also more water-use efficient(Morris & Garrity 1993b). This could also be the case

Utilization of sludge is an attractive option for fertilizing bioenergy crops, since in addition to its valuable macro- and micro-nutrients, it may also contains some pollutants. Therefore, a three-year field experiment was conducted to investigate the suitability of sewage and digested sludge in comparison to synthetic fertilizer on biomass production and its quality in three crop species, with specific attention to the relationship between N availability and biomass accumulation. Fertilizer treatments for each crop species were standardized on the basis of total Nitrogen as follows: maize 120 kg ha−1, fibre hemp 60 kg ha−1 and oilseed rape 90 kg ha−1 Nitrogen. The highest biomass yield of maize (30 Mg ha−1 Dry Mass) and hemp (15 Mg ha−1 Dry Mass) was obtained from the sewage sludge treatment. The sludge treatment also gave the highest leaf Nitrogen mass in biomass of both maize (14 g kg−1) and hemp (18 g kg−1) at 60 DAS (flowering stage). Sewage sludge increased slightly gross energy yield of maize (438 GJ ha−1) and hemp (272 GJ ha−1) in comparison to other treatments. The mass fraction of ash and the combustion-relevant elements such as Chlorine, Potassium, Sodium and Calcium were lower in crops fertilized with sewage sludge than in those fertilized with synthetic fertilizer. In conclusion, sewage sludge produced as high biomass yield as synthetic fertilizers. In addition, it improved growth and quality of biomass.

We studied the effect of different biochar (BC) application rates on soil properties, crop growth dynamics and yield on a fertile sandy clay loam in boreal conditions. In a three-year field experiment conducted in Finland, the field was divided into three sub-experiments with a split-plot experimental design, one for each crop: wheat (Triticum aestivum), turnip rape (Brassica rapa), and faba bean (Vicia faba). The main plot factor was BC rate (0, 5 and 10 t DM ha−1) and the sub-plot factor was the N-P-K fertiliser rate. Soil physico-chemical properties as well as plant development, yield components and quality were investigated. BC addition did not significantly affect the soil chemical composition other than the increased C and initially increased K contents. Increased soil moisture content was associated with BC application, especially at the end of the growing seasons. BC decreased the N content of turnip rape and wheat biomass in 2010, thus possibly indicating an initial N immobilisation. In dry years, the seed number per plant was significantly higher in faba bean and turnip rape when grown with BC, possibly due to compensation for decreased plant density and relieved water deficit. However, the grain yields and N uptake with BC addition were not significantly different from the control in any year. Even though BC application to a fertile sandy clay loam in a boreal climate might have relieved transient water deficit and thereby supported yield formation of crops, it did not improve the yield or N uptake.

Recycling nutrients saves energy and improves agricultural sustainability. Sewage sludge contains 2.6% P and 3.1% N, so the availability of these nutrients was investigated using four crops grown in either soil or sand. Further attention was paid to the role of mycorrhiza in improvement of nutrient availability. The content of heavy metals and metalloids in the feedstock was analyzed. Sewage sludge application resulted in greater biomass accumulation in ryegrass than comparable single applications of either synthetic fertilizer or digested sludge. Sewage sludge application resulted in more numerous mycorrhizal spores in soil and increased root colonization in comparison to synthetic fertilizer. All plants studied had mycorrhizal colonized roots, with the highest colonization rate in maize, followed by hemp. Sewage sludge application resulted in the highest P uptake in all soil-grown plants. In conclusion, sewage sludge application increased feedstock yield, provided beneficial use for organic wastes, and contributed to the sustainability of bioenergy feedstock production systems. It also improves the soil conditions and plant nutrition through colonization by mycorrhizal fungi as well as reducing leaching and need of synthetic fertilizers.

Sewage sludge is rich in essential plant nutrients, but its use is restricted for crop production due to the pollutants it contains, such as metalloids and heavy metals. Sludge is also very sticky and compact. Therefore, the objectives of this work were to evaluate (1) the impact of various amounts of sludge on bioenergy crop productivity and quality and (2) the use of peat as an adjuvant to reduce the stickiness, density and nutrient richness of the sludge. Three different applications of sludge were examined, high, low (50% of high) and low mixed with an equal volume of peat. The sludge–peat mix increased significantly leaf area and biomass accumulation of maize and hemp. High sludge and sludge–peat mix applications increased significantly the leaf area and biomass accumulation as well as the net photosynthesis of oilseed rape. High sludge application resulted in the highest heavy metal and metalloid accumulation in maize and hemp. Sludge–peat mix resulted in the highest heavy metal and metalloid accumulation in oilseed rape. However, the sludge–peat mix application provided the best feedstock quality in all three crops, since chloride, silicon and sulfur concentrations and ash content in plant material were the lowest of the three sludge treatments.

Potassium (K) plays a significant role in preventing outbreaks of pathogenic infections and thereby maintains the photosynthetic leaf area, which supplies assimilates for grain filling. The aim of this research was to investigate the role of K in barley straw anatomy, plant stand architecture, and yield formation. Growth and yield of barley improved with increasing K application rates. This appeared to be due to increased number of spike-bearing tillers, number of grains per spike, and single-grain weight. Straw and walls of cuticle, epidermis, and sclerenchymatous cells thickened in relation to applied K. Thick and firm internodes as well as efficient use of resources resulting from K applications are among key features for good-quality crop production in the field.

Sludge is a good source of plant nutrients, but its use as fertilizer for food or fodder crops is questionable due to its potential content of heavy metals and metalloids. In two pot experiments, germination and growth of maize (Zea mays L., cv. Ronaldino), fiber hemp (Cannabis sativa L., cv. Uso 31) and oilseed rape (Brassica napus L. ssp. oleifera (DC.) Metzg., cv.Wildcat) were studied when treated with sewage sludge and biogas sludge in comparison with chemical fertilizer during 2011. The experiment included five treatments: soil+sewage sludge, soil+fertilizer, sand mixed with peat+sewage sludge, sand mixed with peat+fertilizer, and soil+biogas sludge. Sludge content was calculated to deliver the same content of nitrogen that was added for each species. Germination percentage was recorded at 7, 10 and 14 days after sowing. Length and dry weight of roots and shoots were measured at 14 days after sowing for all species.Sewage sludge treatments resulted in higher germination percentage compared to biogas sludge and fertilizer application in soil and sand mixed with peat. The longest roots were in the sewage sludge treatment. In addition, shoot lengths in maize were highest when fertilized with sludge or fertilizer in soil. Furthermore, sewage sludge or fertilizer added to soil increased root and shoot dry weight of maize. In conclusion, there is an existing excellent potential for using sewage sludge not only as organic matter but also as a valuable plant nutrient source for improving growth of bioenergy crops.

Syyskylvöisten ja monivuotisten kasvien viljelyn edellytyksenä on onnistunut talvehtiminen. Syksyn ja talven aikana kasvien kylmänkestävyys lisääntyy ja kevättä kohti myös niiden vernalisaatiovaatimus täyttyy ja kukinta virittyy. Hyvän talvehtimisen kannalta on tärkeää, että viljelykasveilla on riittävän hyvä kylmänkestävyys ja että ajoitus niiden kukinnan virittymisessä on oikea. Tässä tutkimuksessa selvitettiin syysvehnä, -ruis ja -öljykasvilajikkeiden sekä nurmiheinien kylmänkestävyyden ja kukintavalmiuden kehittymistä Viikissä ja Ylistarossa järjestetyissä kenttäkokeissa. Tulosten perusteella vertaillaan lajien karaistumis- ja vernalisaatioprosessien etenemistä ja selvitetään lajien välisiä eroja niiden kestävyysmekanismeissa ja pohditaan vernalisaation vaikutusta viljelykasvin sadonmuodostukseen. Syksyn karaistumisajan pituus vaikutti ratkaisevasti lajin ja lajikkeen perinnöllisen kylmänkestävyyden ilmenemiseen. Kylmänkestävyys jäi siten heikoksi kaikilla lajeilla syysrypsiä lukuun ottamatta aikaisen lumentulon johdosta. Tutkittavat viljelykasvit poikkesivat huomattavasti niiden kukkimisvalmiuden etenemisessä talven aikaan. Syysvehnällä kukkimisvalmiuden eteneminen oli yhteydessä alentuneeseen kylmänkestävyyteen ja vernalisaatiovaatimuksen täyttyminen pystyttiin mittaamaan muodostuneiden lehtien lukumäärän kautta. Nurmikasveilla vernalisaatiovaatimuksen täyttyminen vaikutti muodostuvien versojen lukumäärään. Vaikutus oli päinvastainen ruokonadalla verrattuna timoteihin tai englannin raiheinään. Tutkimuksen tulosten sekä meneillään olevien jatkotutkimusten perusteella analysoidaan, miten talven aikana tapahtuva vernalisaatio vaikuttaa lajin kylmänkestävyyteen sekä satopotentiaaliin.

SUMMARYAt high northern latitudes, growing seasons are short with long days. In these conditions, tillering is an unwanted trait in barley (Hordeum vulgare L.), because the grains on tillers develop later than those on the main stem and are often harvested before they are fully mature, leading to reductions in overall quality. Hence, the uniculm growth habit has been considered an interesting option for boreal barley production. The aim of the present study was to determine the differences in the yield formation of conventional tillering and uniculm barley, using two pairs of near-isogenic lines and two controls. Uniculm and conventional tillering barley were grown in three experiments conducted at Suitia Experimental Farm, University Helsinki, Finland during 1999–2001. Samples were collected frequently to monitor the biomass and leaf area accumulation. Water-soluble carbohydrate content was analysed at anthesis and at maturity in different plant parts. At maturity, the numbers of spikes/plant and grains/spike were calculated and grain yield weighed. The grain yield of the uniculm barleys was stable over these growing seasons, but it was only half that of the conventional barley cultivars due to the absence of spike-bearing tillers, lower spike grain number and spike weight. In addition, the ability to transport photosynthesized carbohydrates to grains may have been reduced. Thus, it seems that uniculm barleys do not provide further improvement in barley yield.

Water is the primary regulator of yield formation in cereals. The effect of water limitation and its timing on development of yield components were studied in detail at spike and spikelet level in spring barley (Hordeum vulgare L.). An experiment with three watering treatments (control watering, CONT; drought prior to pollination, DR1 and terminal drought, DR2) was set up in a large greenhouse (20 x 30 m). In addition to watering treatments, two NPK fertilizer application rates (0 and 120 kg N ha ―1 ) were used to investigate the fertilizer effect. The drought effect exceeded the effect of fertilizer application for grain number and single grain weight (SGW). DR1 reduced the number of grains, whereas DR2 reduced both SGW and the number of grains. Resuming the watering at pollination (DR1) restored photosynthesis and enhanced grain filling, resulting in almost similar SGW in DR1 and CONT plants. Spikelets in the upper mid-section of the spike dominated yield formation in all treatments. This was particularly emphasised in DR1 plants as 58 % of the grain yield was produced in spikelets 3―5, whereas in DR2 and CONT plants it was 39 % and 36 %, respectively. Hence, drought prior pollination strongly reduced yielding capacity (=grain number) in apical and basal spikelets. DR1 and DR2 reduced substantially grain yield and grain N yield resulting in low nitrogen use efficiency.

Lohkotietopankki on ProAgria Keskusten Liiton ylläpitämä tietokanta, jonne on kerätty lohkokohtaista tietoa käytännön viljelmiltä vuodesta 2002 alkaen. Lohkotietopankkitiedot kattavat lohkokohtaiset viljelytiedot tehdyistä viljelytoimenpiteistä aina saavutettuun satoon ja laatuun sekä taloudellisiin tunnuslukuihin saakka viljelykasveittain. Aineisto mahdollistaa niin tilakohtaisten, alueellisten kuin valtakunnallisten vertailutietojen analysoinnin viljelyn kehittämiseksi sekä kannattavuuden ja kilpailukyvyn parantamiseksi. Lohkotietopankista analysoitiin tietoa rehuohraviljelmiltä vuosilta 2003-2005 viljelyvyöhykkeeltä 1. Tarkastelussa olivat rehuohran keskimääräinen sato lajikkeittain sekä kasvinsuojelun vaikutus satotasoon. Lisäksi tutkimuksessa tarkasteltiin sadon vaikutusta N-, P- ja Ktaseisiin sekä taloudelliseen kannattavuuteen. Tarkastelussa olivat keskimääräisen sadon saaneet tilat (3200 kg/ha) sekä yli 4500 kg/ha saaneet tilat. Kasvinsuojelun vaikutus saatavaan satoon vaihteli lajikkeittain merkitsevästi. Esimerkiksi lajikkeella 'Annabell' sato oli yli 1530 kg/ha parempi tauti- ja laontorjunnan saaneilla lohkoilla kuin käsittelemättömillä lohkoilla, kun taas lajikkeella 'Saana' sato oli 690 kg/ha parempi tautitorjunnan saaneilla lohkoilla, mutta 70 kg/ha alempi laontorjunnan saaneilla lohkoilla verrattuna käsittelemättömiin lohkoihin. Satotason vaikutus N-, P-, ja K-taseisiin oli selkeä. Sadon noustessa yli 4500 kg/ha taseluvut laskivat huomattavasti. Keskimääräisellä satotasolla N -tase oli keskimäärin 40 kg/ha, P-tase 3 kg/ha ja K-tase 7 kg/ha. Sadon ollessa yli 4500 kg/ha N-tase oli 8 kg/ha, P-tase -4 kg/ha ja K - tase -6 kg/ha. Korkean sadon saaneet tilat olivat käyttäneet typpeä lannoituksessa noin 7 kg enemmän kuin keskimääräisen sadon saaneet tilat. Fosfori ja kaliumlannoituksessa ei ollut merkitsevää eroa. Satotaso vaikutti tilojen taloudelliseen tulokseen. Muuttuvat kustannukset olivat yli 4500 kg:n hehtaarisadoilla noin 40 euroa korkeammat kuin keskimääräisen sadon tiloilla. Erot muuttuvissa kustannuksissa johtuivat erityisesti korkeammista kasvinsuojelu- ja siemenkustannuksista. Kuitenkin tarkasteltaessa katetuotto A:ta ilman tukia, taloudellinen tulos oli 3200 kg/ha saaneilla tiloilla noin 140 euroa pienempi. Lohkotietopankkiaineiston perusteella voidaan havaita, että hyvän satotason ja taloudellisen tuloksen saaminen edellyttää lajikeominaisuuksien tuntemista, tarpeenmukaista kasvinsuojelua sekä oikein ajoitettuja viljelytoimia. Pellon kasvukunto, sääolot sekä viljelijöiden osaaminen vaikuttavat lisäksi kasvinviljelystä saatavaan satoon, ravinnekuormitukseen sekä taloudelliseen tulokseen.

Legumes are an important component of sustainable crop rotations around the world, but are under-represented in European agriculture. Finnish use of grain legumes is exceptionally low. These experiments were initiated to test the possibility of extending the range of grain legumes that can be grown in Finland. A small range of germplasm of blue lupin, white lupin, lentil and some other annual species were tested in a trial that also included familiar cultivars of faba bean. Faba bean yields were 6.0 – 7.3 Mg ha-1, blue lupin yields 3.3 – 4.8 Mg ha-1. Two of the cultivars of blue lupin reached maturity in a timely fashion, showed little disease and did not lodge, so they have potential for use in the national agricultural system. Lentils also ripened, but presented management problems that require further investigation. White lupin showed potential as a producer of biomass, with one cultivar exceeding 18 Mg ha-1 dry matter.

Eri bioenergiantuottotavat asettavat kasvibiomassalle erilaisia vaatimuksia. Biologiset, käymiseen perustuvat menetelmät käyttävät liukoisia sokereita ja tärkkelystä lähteinään. Näissä menetelmissä biomassan epäorgaanisia yhdisteitä sisältävä jäänne voidaan hyödyntää rehuna ja lannoitteina, ja biomassan kosteuspitoisuus aiheuttaa ongelmia vain satoa varastoitaessa. Termokemiallisia menetelmiä käytettäessä sen sijaan kosteuden haihduttamiseen kuluu energiaa ja biomassan sisältämät alkuaineet voivat vaikuttaa prosessissa muodostuvan tuhkan ominaisuuksiin. Kertyvä kuona hidastaa laitteiston lämmönsiirtokykyä ja syövyttää putkia. Erityisesti korkeat pii- ja alkalimetallipitoisuudet (K ja Na) ja korkea klooripitoisuus (Cl) lisäävät polttolaitteiston ylläpitokustannuksia. Olemme Helsingin yliopiston Soveltavan biologian laitoksella selvittäneet eri kasvien sopivuutta bioenergian raaka-aineeksi määrittämällä biomassatuotannon lisäksi kasvibiomassasta tuhka-, hiili-, typpi-, sekä alkuainepitoisuudet. Kasvibiomassan hiili- ja typpipitoisuudet ovat olleet kasvilajista riippumatta yleensä 41- 45 % (C) ja 0,6-3 % (N) kuiva-aineesta. Tässä raportissa kerromme bioenergiatarkoitukseen kasvatettujen kuitu- ja öljyhampun, sekä rehumaissin analyysituloksista. Näiden lisäksi tulemme tekemään analyysejä myös maa-artisokan versoista ja mukuloista, sekä valkolupiinin versoista. Tulostemme mukaan hiilen määrä on tasaisesti jakautunut maissin maanpäällisissä osissa tyvestä latvaan, kun taas typen ja fosforin (P) määrät ovat korkeammat kehittyvissä tähkissä ja verson latvuksessa. Kloorin (Cl) ja kaliumin (K) pitoisuudet puolestaan vähenivät jyrkästi kohti latvusta. Maissin K- ja Cl-pitoisuudet olivat yli kaksinkertaiset hampun K- ja Cl-pitoisuuksiin verrattuna. Öljyhamppu puolestaan sisälsi noin 5-kertaisen määrän kalsiumia Ca verrattuna maissiin. Öljyhampun ja kuituhampun alkuainepitoisuudet poikkesivat myös suuresti. Useimpien alkuaineiden pitoisuudet olivat kuituhampussa matalampia kuin öljyhampussa.

Sewage sludge is rich in organic matter, and plant nutrients such as nitrogen, phosphorus and potassium. Nevertheless, using sludge as fertilizer for crops to produce food or feed is limited due to the presence of trace contaminants such as heavy metals. Therefore, the aim of this study was to investigate the use of sewage sludge as a nutrient source for bioenergy crops such as fibre hemp, oilseed rape and white lupin. Specific attention is paid to the biomass accumulation and the quality of the plant material as well as the ability of the crops to take up the heavy metals from soils in order to ensure that the amount of pollutant does not cumulate. Fibre hemp (Cannabis sativa L.) cv. Uso, oilseed rape (Brassica napus L.) cv. Wildcat and white lupin (Lupinus albus L.) cv. Amiga were sown in 5-L pots in a greenhouse. Three potting mixes were used: a standard peat-based potting compost with 50% sludge, sludge with peat (50%:50% by weight), or 100% sludge, and a constant mass of 666 g potting mix per pot. Dry weight of plants and leaf area were measured four times during the growth of fibre hemp and oilseed rape and at maturity of white lupin. Net photosynthesis and leaf temperature of plants were measured three times. Ash content and elemental analysis was made from samples collected at harvest. Sewage sludge application significantly affected most parameters measured. In fibre hemp, maximum dry weight, leaf area and photosynthesis values were obtained from the sludge – peat treatment. In oilseed rape, the maximum values of dry weight of plant, leaf area, photosynthesis, number of siliques per plant and number of seeds per plant were obtained from the 100% sludge treatment. However, the highest number of branches per plant, weight of siliques per plant, seed weight per plant and whole plant weight were obtained from the sludge – peat treatment. In white lupin, the sludge – peat treatment resulted in highest net photosynthesis, number of pods per plant, number of seeds per plant and whole weight plant at harvest. Highest sludge application resulted in highest heavy metal concentration in plant material of fibre hemp and white lupin. However, high heavy metal concentration in oilseed rape were obtained when sludge was mixed with peat. It is concluded that sewage sludge is suitable for use as a nutrient source for bioenergy crops studied. In future experiments we will estimate the optimum level of sewage sludge for each one of these crops and determine its potential for use in field conditions.

Water and nitrogen (N) availability are the main factors influencing crop growth globally. Poorly distributed or insufficient water for crop growth requirements decreases yields in drought-prone areas such as those with a Mediterranean type environment. Cereal grain yield is a complex trait of interrelated components: plants per unit land area, spikes per plant, spikelets per spike, grains per spikelet, and single grain weight (SGW). The effect of water limitation and timing on development of yield components was studied in detail at the spike level in spring wheat (Triticum aestivum L.) cultivar Amaretto. An experiment with three watering treatments (control watering, CONT; drought prior to pollination, DR1 and terminal drought, DR2) was arranged in a large greenhouse (20 m × 30 m), with the use of standard field-trial machinery. Automated blackout curtains were used to control day length, which was set to correspond to that at 40°N. With watering treatments, two N application rates (60 and 120 kg N ha−1) were used to investigate the N effect and potential watering × N interaction on yield formation and realisation. The water deficit effect exceeded the effect of N on fertile floret and grain number and SGW. DR1 strongly reduced the number of fertile florets and grains, whereas terminal drought reduced the number of grains per spike. Resuming the watering at pollination markedly enhanced photosynthesis, and hence grain filling capacity, resulting in the highest SGW in DR1. Enhancement in availability of key resources was associated with reduced rate of fertile floret and grain abortion, which resulted in higher grain to fertile floret ratio in DR1. Spikelets in the mid-section of the spike dominated yield formation in all treatments. In DR1 this was especially emphasised as 53% of the grain yield was produced in spikelets 4–6, whereas in DR2 and CONT this was 45 and 41%, respectively. Grains in proximal position in the spikelets produced about 80% of the spike grain yield, the proportion being slightly higher in stressed plants and plants receiving 60 kg N. No marked N × water deficit treatment interaction occurred for any of the measured parameters.

Maize ovary development is linked to kernel formation. Soil water deficit results in ovary abortion because of low water potential (Ψ w ) resulting in inhibition of photosynthesis from anthesis to silking stage. Thus, drought is a key factor causing yield losses in maize, especially near the time of pollination. Earlier studies have indicated that selenium (Se) maintains antioxidative defence systems and enhances sugar and starch accumulation. The effects of Se on maize ovary development were studied in drought stress conditions. Maize ovary development was studied through observations on starch, membrane integrity, fresh weight and dry weight in drought-treated or unstressed glasshouse-grown plants, and crop yield, yield structure, leaf, stem and ear biomass accumulation were also analyzed. Results indicated that Se increased the stress tolerance of the crop, even though ovary abortion was not eliminated by Se treatments under low Ψ w . Under well-watered control conditions, Se had also negative effects. When the first ear was not succesfully pollinated or the ovaries aborted, the plants developed more ears. Even though these later formed ears did not produce kernels, they significantly increased the dry weight of the plants under water deficit. It could be concluded that The optimal concentration for maize of Se applied through roots is about 0.01 mg kg −1 (supplied as Na 2 SeO 4 ) soil or less.

Nurminataa käytetään pääasiallisesti rehunurmien siemenseoksissa. Se onkin toiseksi eniten viljelty rehunurmikasvi timotein jälkeen. Nurminata on nopeakasvuinen, kestää toistuvaa niittämistä lyhyeen sänkeen ja on kilpailukykyinen. Sen rehulaatu ei kuitenkaan ole timotein luokkaa, minkä lisäksi se ei menesty hiekkaisilla mailla ja on arka kuivuudelle. Nurmirehun tuotannossa kotimaista, mieluiten paikallista alkuperää, olevan kylvösiemenen käyttö on suositeltavaa. Paikallisesti tuotettu kylvösiemen edesauttaa mm. kasvuston talvehtimista ja sadontuottokykyä. Nurminadan siemensadot ovat havaintojen mukaan laskeneet viimeisten kymmenen vuoden kuluessa. Tässä tutkimuksessa selvitettiin vanhan ja uuden nurminatalajikkeen satokomponenttien muodostumisessa esiintyviä eroja ja niiden selityskykyä siemensadolle. Tutkimuksessa käytettiin vanhaa, Kalevi, ja uutta, Fure, nurminatalajiketta. Määritimme nurminadoista niiden biomassan muodostuksen toisena kasvukautena toistuvin mittauksin, sadon osatekijät (mm. korsien, lehtien ja röyhyjen massat, versojen röyhyjen ja siementen lukumäärät sekä kukkien, tähkylöiden ja siementen muodostuksen) ja siemensadon. Lisäksi kasvustoista analysoitiin rehulaatu kahdesti (mm. D-arvo, raakaproteiini, kuiva-aine ja tuhka). Tulosten perusteella Fure muodostaa lehtevämmän kasvuston kuin Kalevi. Vaikka Kalevin kokonaisversomäärä on suurempi kuin Furen, Fure muodostaa Kalevia enemmän vegetatiivisia versoja ja sen biomassasta suurempi osa on lehdissä kuin Kalevilla. Fure muodostaa myös Kalevia enemmän tähkylöitä, kukkia ja siemeniä röyhyä kohden. Lajikkeiden siemensadossa ei silti ollut merkittävää eroa, joten ne pystyvät tehokkaasti kompensoimaan satokomponenteissa tapahtuvia muutoksia kuten viljat. Röyhyjen määrän lisääntyminen laski Kalevin siemensatoa samoin kuin siementen määrän lisääntyminen röyhyssä Furella. Biomassan lisääntyminen korrenkasvuvaiheen alussa vähensi Furen siemensatoa ja lisäsi Kalevin siemensatoa. Lajikkeiden rehulaadussa ei havaittu muita eroja kuin se, että Kalevin D-arvo pysyi pitempään korkeampana kuin Furen.

Syysrypsi on varteenotettava vaihtoehto rypsille. Sen viljelyssä ongelman muodostaa kuitenkin kevätja syysmuotoisista viljelykasveista poikkeava kylvöajankohta, heinäkuu, mistä johtuen se joudutaan useimmiten kylvämään kesantoon. Toinen merkittävä ongelma on sen heikohko talvehtiminen. Seosviljely saattaisi parantaa paitsi syysrypsin tuotannon kannattavuutta myös kasvuston talvehtimista. Syysrypsi voidaan kylvää keväällä samanaikaisesti kevätviljan kanssa, jolloin viljasato korjattaisiin syksyllä kasvuston tuleennuttua ja rypsisato seuraavana vuonna. Tällöin maanmuokkauksen tarve myös vähenisi. Seoskasvustojen etuna voidaan pitää kasvuston tehokkaampaa resurssien hyödyntämistä, erityisesti ravinteiden käytön tehostumista, sekä puhdaskasvustoja vähäisempää kasvintuhoojien esiintymistä. Seoskasvustojen haittoina voidaan pitää eri kasvilajien välistä kilpailua, mikä voi vaikuttaa paitsi sadon määrään myös sen laatuun. Toisaalta valitsemalla seoksiin kasvilajeja, joiden kehitysrytmi poikkeaa selvästi toisistaan, kuten kevät- ja syysmuotoisten kasvilajien, kilpailua voidaan vähentää. Tämä perustuu siihen, että kevätmuotoisen kasvilajin alkaessa tuleentua syysmuotoinen kasvilaji alkaa vasta tehokkaasti muodostaa biomassaa. Tällöin kevätmuotoinen kasvilaji pystyy muodostamaan kasvustonsa lähes kokonaan ilman kilpailua erityisesti koskien maapäällisiä kasvuston osia. Toisena kasvuvuotenaan syysmuotoisella viljelykasvilla puolestaan ei enää ole kilpailevaa kasvilajia. Selvitimme tutkimuksessamme mahdollisuutta kylvää syysrypsiä keväällä seoskasvustona ohran kanssa sekä seoskasvuston vaikutusta ohran kasvuun ja satoon sekä syysrypsin kasvuun ja erityisesti talvehtimiseen. Tulosten perusteella näyttäisi siltä, että kevätviljojen, tässä tapauksessa ohran, ja syysrypsin seosviljely onnistuu seoskasvustona. Ohra kuitenkin johti syysrypsin kasvutiheyden harvenemiseen ensimmäisen kasvukauden aikana, joten seoskasvustoja käytettäessä syysrypsin kylvötiheyttä tulisi lisätä. Syysrypsin sadonmuodostuksen kannalta haitallista kukkavarren kehittymistä ei tapahtunut ensimmäisenä kasvukautena huolimatta kevätkylvöstä. Seoskasvustona kylvetyt kasvustot myös talvehtivat paremmin kuin rinnakkaisessa kokeessa olleet puhdaskasvustot, jotka tuhoutuivat ensimmäisenä vuonna täysin. Suurimman ongelman syyrypsin kannalta muodostivat toisena kasvukautena sillä jänikset, rusakot ja peurat söivät kasvustot niiden alettua muodostaa kukkavarsia ja linnut söivät jäljelle jääneistä kasveista siemenet niiden alkaessa täyttyä. Syysrypsi hankaloitti aluskasvustona monitahoisen ohran puintia ohran lakouduttua ja piti kasvuston kosteana ensimmäisessä kokeessa. Toisessa kokeessa syysrypsi ei aiheuttanut sadonkorjuuongelmia. Syysrypsi ei juurikaan vaikuttanut ohrasatoon tai sen laatuun.

The ideotype of a crop is a model of a plant community where all necessary and beneficial traits for crop performance in a particular environment are combined. It is important to consider the environment when developing an ideotype since climatic, edaphic and agronomic features of the target region have a major role in determining crop performance. New technologies, high yielding cultivars, irrigation and water management, plant protection materials and more skilful farm management practices have increased yields and yield potentials on cereals in Finland as in many other countries. In this paper we aim to summarize traits which would be useful from the farmers’ perspective. The most important trait is increased early vigour of spring cereals, including faster rate of early development and increased leaf area to improve both the resource capture of the canopy and water use efficiency. Introduction of dwarfing genes would improve lodging resistance and harvest index due to improved partitioning of dry matter into grains whereas longer coleoptiles would improve emergence and seedling establishment. Improved ability of crops to utilize stem reserves during grain filling would increase resistance against environmental stresses. All of these traits would also increase the competitive ability of the plant against weeds as well as competition within the crop canopy and are already available from non-adapted germplasm of the various spring cereal species., Ideotyypillä tarkoitetaan kasvustoa, jossa yhdistyvätkaikki tarvittavat ja hyödylliset ominaisuudet hyvälaatuisen ja korkean sadon tuottamiseksi tietyssä kasvuympäristössä. Kasvuympäristön huomioiminen on erityisen tärkeätä ideotyyppiä hahmoteltaessa, sillä ilmastolla sekä edafisilla ja agronomisilla tekijöillä on keskeisin rooli kasvuston menestymisessä. Uudet viljelymenetelmät, ravinteet, satoisat lajikkeet, kastelu, kasvinsuojeluaineet sekä huolellinen viljelytoimien suunnittelu ja toteutus ovat parantaneet kevätviljojen satoja niin Suomessa kuin muuallakin maailmassa. Lajikkeita on kuitenkin kehitettävä edelleen erityisesti kasvinsuojeluaineiden ja typen käytön aiheuttaman ympäristökuormituksen vuoksi. Tarkastelemme tässä artikkelissa ominaisuuksia, jotka vaikuttavat keskeisesti elinvoimaisen ja hyvän kasvuston kehittymiseen ja menestymiseen ja samalla mahdollistavat panosten käytön vähentämistä kasvintuotannossa. Tarkastelun kohteena ovat siten kasvuston nopea ja elinvoimainen alkukehitys, sivuversojen muodostuminen, kääpiö- ja puolikääpiölajikkeet, veden- ja typenkäytön tehokkuus, korsivälivarastot sekä kasvuston kilpailukyky. Elinvoimainen kasvusto peittää maan nopeasti, mikä lisää kasvuston kilpailukykyä rikkakasveja vastaan ja samalla parantaa vedenkäytön tehokkuutta ja säästää maan vesivaroja. Kääpiömuotoja hyödyntämällä voidaan paitsi vähentää lakoutumista myös tehostaa hiiliyhdisteiden jakautumista kehittyviin jyviin korsien ja juurien sijaan. Keskittämällä sivuversojen muodostuminen yhteen tai kahteen tähkälliseen tai röyhylliseen sivuversoon voidaan edelleen tehostaa yhteyttämistuotteiden jakautumista sekä vedenkäyttöä. Erityistä huomiota tulisi kiinnittää kasvien kykyyn hyödyntää korsivälivarastoja jyväntäyttymisjakson aikana, koska sääolot ovat Suomessa usein hyvin vaihtelevat. Korsivälivarastoja hyödyntämällä jyväntäyttymistä voidaan jatkaa keskeytyksettä lähes sääoloista riippumatta. Kun kiinnitetään huomiota lajikkeiden valintaan ja viljelymenetelmiin, satotasoja ja keskisatoja on mahdollista nostaa Suomessa tulevaisuudessakin.

Rotation with dicotyledonous crops to break cereal monoculture has proven to be beneficial to successive cereals. In two fields where the soil had been subjected to prolonged, continuous cereal production, two 3-year rotation trials were established. In the first year, faba bean, turnip rape and barley were grown, as first crops, in large blocks and their residues tilled into the soil after harvest. In the following year, barley, buckwheat, caraway, faba bean, hemp and white lupin were sown, as second crops, in each block and incorporated either at flowering stage (except barley) or after harvest. In the third year, barley was grown in all plots and its yield and grain protein concentration were determined. Mineral N in the plough layer was determined two months after incorporation of crops and again before sowing barley in the following year. The effect of faba bean and turnip rape on improving barley yields and grain protein concentration was still detectable two years after they were grown. The yield response of barley was not sensitive to the growth stage of second crops when they were incorporated, but was to different second crops, showing clear benefits averaging 6-7% after white lupin, faba bean and hemp but no benefit from caraway or buckwheat. The effect of increased N in the plough layer derived from rotation crops on barley yields was minor. Incorporation of plants at flowering stage slightly increased third-year barley grain protein concentration but posed a great potential for N loss compared with incorporation of crop residues after harvest, showing the value of either delayed incorporation or using catch crops.

Ravinteiden tehokas hyväksikäyttö on kestävän kasvintuotannon kannalta keskeistä. Lähes kaikki tutkimus on keskittynyt kuitenkin typpeen ja fosforiin lähinnä näiden aiheuttamien ympäristöhaittojen vuoksi. Sadontuoton ja erityisesti laadun kannalta kalium ja erityisesti kalium:kalsium-suhde ovat tärkeitä tekijöitä. Nykyiset käytössä olevat lannoitussuositukset perustuvat kaliumin osalta vanhoihin selvityksiin, joissa ei ole kiinnitetty niinkään huomiota kaliumin vaan typen ja fosforin tarpeeseen. Eri genotyyppien välillä tiedetään esiintyvän suurta vaihtelua kaliumin hyväksikäytössä, joten ympäristönäkökannan lisäksi voitaisiin parantaa myös viljelyn kannattavuutta tarkennettaessa kasvuston kaliumin tarve. Teollisuus puolestaan tarvitsee korkealaatuista viljaa raaka-aineeksi. Tähän voidaan pyrkiä sekä viljelyteknisin että jalostuksellisen toimin, huomioimalla modernien viljalajikkeiden erityistarpeet mm. ravinteiden käytön suhteen ja käyttämällä elinvoimaista siementä. Elinvoimainen siemen takaa tasaisen alkuunlähdön orastumisvaiheessa parantaen välillisesti sadon laatua. Kalium saattaa puolestaan lisätä siemenen elinvoimaa. Tutkimuksen tarkoituksena oli selvittää kaliumin ja kalium:kalsium-suhteen merkitystä ohran kasvustorakenteeseen, jyväntäyttymiseen ja siemenen elinvoimaan päämääränä laadullisesti ja määrällisesti tasaisen sadon, suuren jyväkoon ja elinvoimaisen siemenmateriaalin saavuttaminen. Koe järjestettiin kasvihuoneella Helsingin yliopiston soveltavan biologian laitoksella astiakokeena. Ohra kylvettiin lannoittamattomaan, kalkittuun kasvuturpeeseen 7.5 L altakasteluastioihin. Astioihin lisättiin 50, 100, 200 ja 800 mg K L-1. Peruslannoituksena annettiin lisäksi 250 mg N L-1, 50 mg P L-1 ja 33 mg Ca L-1. Kalsiumia annettiin joko peruslannoituksen 33 mg L-1 tai suurempi lannoitus, jolloin Ca lisättiin lisäksi viisi kertaa K lannoitusta vastaava määrä. Koe oli täydellisesti satunnaistettu ja siinä oli kuusi toistoa. Kasveista havainnoitiin itävyys, sivuversoista ja pääversoista biomassan ja lehtialan muodostus, lehtialan kesto, tautien esiintyminen, korrenseinämän paksuus ja kasvin pituus, jyväpaino- ja lukumäärä sekä vesisuhteet, yhteyttäminen ja klorofyllipitoisuus. Kaliumpitoisuuden kohotessa kasvien lehtiala kasvoi ja lehtialan kesto piteni. Kasvien biomassa oli jopa kolme kertaa suurempi korkeissa kaliumpitoisuuksissa kuin matalissa. Korrenseinämän paksuus kasvoi kaliumpitoisuuden kasvaessa ja silmämääräisten havaintojen perusteella kasvusto oli tukevampi korkeissa kaliumpitoisuuksissa. Tähkä- ja jyväpaino oli lähes puolet korkeampi korkeissa kaliumpitoisuuksissa kuin matalissa. Sienitauteja esiintyi eniten matalissa kaliumpitoisuuksissa. Kalium ei vaikuttanut kasvuston kehittymisrytmiin. Kaliumia esiintyy viljoilla eniten korsissa, koska se on solujen rakennusaine. Kaliumia tarvitaan myös solun aineenvaihdunnassa kontrolloimaan ionitasapainoa entsyymiaktiivisuuden ylläpitämiseksi. Kalium toimii joidenkin entsymaattisten reaktioiden kofaktorina. Kalium säätelee myös ilmarakojen toimintaa, jolloin se vaikuttaa välillisesti yhteyttämiseen. Lisäksi kaliumilla on tärkeä rooli sokerien kuljetuksessa korsista ja lehdistä jyviin. Täten kaliumilla on ensisijainen rooli jyväntäyttymisessä ja jyväkoon säätelyssä. Havaittu jyväpainon nousu onkin selvä osoitus kaliumin roolista kasvustorakenteen ja sadon osatekijänä. Kaliumlisäyksellä saavutettu korkeampi jyväpaino saattaa selittyä suuremman biomassan ja vähäisemmän tautien esiintymisen kautta yhteyttämistuotteiden saatavuuden paranemisella.

• Background and Aims Shade or inadequate water can inhibit photosynthesis and limit the development of maize (Zea mays) ovaries around the time of pollination, potentially reducing the number of kernels at harvest. This study investigated whether the decreased photosynthesis diminished only the sugar supply or also altered the transport path to the ovaries. • Methods Photosynthesis and water potentials (Ψw) were measured in the leaves while dry matter delivery was monitored in the ovaries. Ovary glucose, starch and acid invertase activities were measured in situ. Stems were fed xylem-mobile safranin or phloem-mobile carboxyfluorescein (CF), and the dye transport to the ovaries was determined. • Key Results Under normal conditions, the ovaries gained in dry mass, and starch accumulated in the pedicel and ovary wall. Glucose accumulated in the pedicel, apparently in the apoplast where insoluble (cell-wall-bound) acid invertase acted on the arriving sucrose. A glucose gradient developed from pedicel to nucellus. Safranin moved in the xylem and did not reach the ovary, but CF moved in the phloem and arrived at the ovary. CF also spread into the pedicel but unlike glucose it did not enter the nucellus. Low Ψw or shade decreased leaf photosynthesis, ovary dry mass accumulation, invertase activities, pedicel glucose, starch accumulation and CF delivery. Removal of these treatments reversed the effects. • Conclusions The success of CF in tracing the general path and rate of carbohydrate transport gave visual evidence that phloem transport to the ovary decreased at low Ψw or in the shade but otherwise remained functional. The decreases indicated that losses in carbohydrate delivery are central features of failed ovary development under these conditions. The selectivity of transport into the nucellus resembled the situation later when embryo and endosperm are present and selective uptake occurs from the apoplast.

To elucidate the contribution of dehydrins (DHNs) to freezing stress tolerance in Arabidopsis, transgenic plants overexpressing multiple DHN genes were generated. Chimeric double constructs for expression of RAB18 and COR47 (pTP9) or LTI29 and LTI30 (pTP10) were made by fusing the coding sequences of the respective DHN genes to the cauliflower mosaic virus 35S promoter. Overexpression of the chimeric genes in Arabidopsis resulted in accumulation of the corresponding dehydrins to levels similar or higher than in cold-acclimated wild-type plants. Transgenic plants exhibited lower LT50 values and improved survival when exposed to freezing stress compared to the control plants. Post-embedding immuno electron microscopy of high-pressure frozen, freeze-substituted samples revealed partial intracellular translocation from cytosol to the vicinity of the membranes of the acidic dehydrin LTI29 during cold acclimation in transgenic plants. This study provides evidence that dehydrins contribute to freezing stress tolerance in plants and suggests that this could be partly due to their protective effect on membranes.