Nitrogen leaching and herbage production on intensively managed grass and grass-clover pastures on sandy soil in Finland

The main aim of this study was to compare the N leaching from grass fertilized with 220 kg N ha⁻¹ and grass‐clover pastures receiving no fertilization during three grazing years and a renewal year, in a 4‐year ley rotation. The other aim was to compare the herbage and milk production of these pastures. The study was conducted on a lysimeter field; five lysimeters (size 10 × 10 m) were assigned to each treatment. Automated drinking water outlets for the cows were located on one of the lysimeters on each treatment. The amount of leachate was recorded and composite samples were analysed for total N, NO₃‐N, NH₄‐N and soluble organic N (SON). The number of grazing cows was adjusted according to the herbage mass production. The amount of milk was measured. The total input of N to the area was 290 and 215 kg N ha⁻¹ year⁻¹ for grass and grass‐clover treatments, respectively. The total N leaching during grazing years was 17 and 9 kg N ha⁻¹ from grass and grass‐clover treatments, respectively. Renewal of the sward increased N leaching in both treatments, up to 60 and 40 kg total N ha⁻¹ in grass and grass‐clover treatments, respectively. During the grazing years 96% of the leached N was in the form of NO₃‐N, but during the renewal year the proportion of NO₃‐N was lowered to 89% and the rest was in the form of SON. The total amount of N in the surface runoff was 3–5 kg ha⁻¹ year⁻¹. As high N fertilizer rates per application are a common practice in Finland, short‐term grass‐clover pastures can be considered environmentally beneficial when compared with intensively fertilized grass pastures in comparable circumstances.     

Degradation and Leaching of Simazine in Arctic Sandy Soils

Abstract

Degradation and leaching of ¹⁴C-labelled simazine in coarse sandy soils at 15 + 1°C were investigated using radiometric and mass-spectrometric methods. During 6 months incubation approx. 4–7% of the applied ¹⁴C-simazine was evolved as ¹⁴CO₂. 4–9% of the simazine still remained in the soil. Addition of hen manure or acidification by addition of peat did not clearly influence the rate of degradation of simazine, whereas mechanical treatment significantly increased its degradation. In a nitrogen atmosphere the rate of degradation of simazine was reduced.

9–15% of the simazine or its radioactive metabolites leached through a 33 cm sandy moraine soil column (diameter 6 cm) in ca. 1770 mm of precipitation over a 4 month period, and 2% was leached from a fine sand soil under the same conditions.     

Use of human urine fertilizer in cultivation of cabbage (Brassica oleracea)--impacts on chemical, microbial, and flavor quality

Human urine was used as a fertilizer in cabbage cultivation and compared with industrial fertilizer and nonfertilizer treatments. Urine achieved equal fertilizer value to industrial fertilizer when both were used at a dose of 180 kg N/ha. Growth, biomass, and levels of chloride were slightly higher in urine-fertilized cabbage than with industrial-fertilized cabbage but clearly differed from nonfertilized. Insect damage was lower in urine-fertilized than in industrial-fertilized plots but more extensive than in nonfertilized plots. Microbiological quality of urine-fertilized cabbage and sauerkraut made from the cabbage was similar to that in the other fertilized cabbages. Furthermore, the level of glucosinolates and the taste of sauerkrauts were similar in cabbages from all three fertilization treatments. Our results show that human urine could be used as a fertilizer for cabbage and does not pose any significant hygienic threats or leave any distinctive flavor in food products.     

Injuries to scots pine mycorrhizas and chemical gradients in forest soil in the environment of a pulp mill in central Finland

The occurrence and condition of Scots pine mycorrhizas were studied at different distances from a pulp mill in Central Finland. The chemical analyses of the soil humus layer in the vicinity of the mill revealed increased levels of ammonium-nitrogen, sulphur and calcium but unaltered concentrations of phosphorus and magnesium. Higher nitrate levels and nitrification were clearly detected at some sites which had recently been limed. Significant decreases in root ramification index and number of living mycorrhizas were found in a zone 0–0.6 km zone surrounding the factory but these parameters increased with increasing distance. Within a 2 km zone around the mill there were abundantCenococcum geophilum andPaxillus involutus-type mycorrhizas while lowered frequencies of several other mycorrhizal types were detected. An ultrastructural study revealed changes in several types of mycorrhizas, the clearest of which were increased tannin deposition in cortical cells, intracellular growth of hyphae in cortical cells and the appearance of electron dense accumulations in the vacuoles of the fungal cells. The ultrastructural changes observed were distributed at least to a distance of 3 km from the mill and occurred in the roots of trees that had only a slight loss of needle mass. Nitrogen deposition is suspected to be the primary cause of root decline but atmospheric S0₂ through the tree crown is also likely to be a contributing factor.     

Flea beetle (Chrysomelidae: Alticinae) species composition and abundance in different cruciferous oilseed crops and the potential for a trap crop system

Flea beetles are significant insect pests of cruciferous oilseed crops in northern Europe. A two-year small-scale field experiment was performed to determine the species complex and abundance of flea beetles (Chrysomelidae: Alticinae) associated with eight cruciferous oilseed plants: Brassica juncea (L.) Czern., Brassica napus L. var. oleifera subvar. annua, Brassica nigra (L.) Koch, Brassica rapa L. var. oleifera subvar. annua, Camelina sativa (L.) Crantz, Eruca sativa Mill., Raphanus sativus L. spp. oleifera (DC) Metzg. and Sinapis alba L. Their relative attractiveness to flea beetles was compared to assess their potential for use within a trap crop system for spring oilseed rape. Adults of six species of flea beetles were found on the test plants. Phyllotreta undulata Kutsch. was the most abundant species followed by Phyllotreta nigripes (Fabr.), Phyllotreta nemorum L. and Phyllotreta vittata (=striolata) (Fabr.), while Phyllotreta atra (Fabr.) and Chaetocnema concinna Marsh. were occasionally present. The species composition of flea beetles on seven of the investigated plant species was fairly similar but differed significantly on C. sativa. The flea beetle species discriminated between the tested host plants, with a general gradient in attraction from E. sativa > B. juncea > B. nigra > R. sativus > S. alba > B. rapa > B. napus through to C. sativa. Brassica juncea and B. nigra developed faster and at early growth stages were more attractive to overwintered adult flea beetles than B. napus and therefore had potential as trap plants to protect spring rape. R. sativus and E. sativa, despite their development rate being slower than B. napus were also more attractive to flea beetles. Thus, further experiments with a complex of attractive early season and late-season plant species (multiple trap crops) should be undertaken.     

The effect of the annual use of some pesticides on soil microorganisms,pesticide residues in soil and carrot yields

The study deals with the effect of common, annually-used pesticides on soil microorganisms, pesticide residues in soil, and carrot (Daucus carota) yields in Central Finland. Linuron residues in carrot roots were also analysed. Thiram+lindane and dimethoate were applied from 1973–1981 at the commercially recommended doses on experimental plots of carrots, linuron was applied at twice the recommended rate from 1973–1979 and at the normal rate thereafter and in addition TCA was applied in 1978. Maleic hydrazide was used in the years 1973–1976, and glyphosate after 1977. The numbers of different soil microorganisms, their activities and the pesticide residues were studied from autumn 1978 to 1981. The pesticide treatments reduced the growth of soil algae but increased the total number of microorganisms and the number of aerobic spore-forming bacteria. Linuron residues in the soil were 0.9–2.8 mg kg^?1 in the growing season and 1.2–1.7 mg kg^?1 in the autumn, 3 months after application. The residues of glyphosate in the soil were 0.7 mg kg^?1 in the autumn, 41 days after the treatment, and had declined to a level of about 0.2 mg kg^?1 by the following summer. In the pesticide-treated plots the carrot yield was only 20–60% of the yield in the hand-weeded plots. The herbicide programme controlled most of the annual weeds but not couchgrass Elymus repens and milk sow-thistle Sonchus arvensis.     

Methods to reduce pathogen microorganisms in manure

Manure always contains microorganisms originating from faeces, bedding material, feed residues, etc. A small percentage of the enteric microorganisms are pathogens, some of them being obligate parasites so that they can no more multiply outside of their hosts. If these pathogen microorganisms gain access to other sensitive host, water or vegetation, there will be health risks for animals or human. Some microorganisms in manure can increase the risks for deterioration of fodder if manure should contaminate fodder and these microorganisms can be secreted into raw milk. In particular, the cheese industry can encounter difficulties from butyric acid producing clostridia present in manure.

The reduction and controlling of microorganisms can be done by microbiological, chemical or physical methods. The efficiency as well as the advantages and disadvantages of these methods will be discussed. Some methods may give other beneficial products, thus providing novel opportunities for new sources of farm income. All methods do require investments and have operational costs thus the selection becomes dependent f. i. how long animal breeding will be practised. Some methods fit better for seasonal or temporal use. The method selected depends also on the form of the manure as well as on the size of the animal unit.

The hygiene control claims of EU will be critically discussed.     

Aeration improves the hygiene of cattle slurry and the quality of grass forage and silage†

The aeration of slurry at mesophilic temperature improves its hygiene, provided no fresh slurry is added to the tank during the 3–4 weeks of aeration. Microorganisms, such as Listeria monocytogenes, Yersinia enterocolitica and related species and coliphages, were reduced by 90–99.9%. However, the number of Clostridium was not affected. The typical odour of slurry diminished. The use of aerated slurry as fertilizer on growing grass may cause less risk of contamination either by enteric microorganisms or by butyric acid‐producing clostridia than the use of non‐aerated slurry. The hygiene level of grass was also sufficient when grown in a cold, rainy late summer and used for silage. None of the 62 samples of silage prepared from a second‐harvest grown in rainy conditions and fertilized with aerated slurry were found to have deteriorated. However, three samples out of 63 made during the same period but fertilized with non‐aerated slurry were observed to have deteriorated completely. Neither spreading method, band‐spreading or injection of the slurry into sward, had any effect on the microbiological hygiene of the samples.     

Selecting appropriate faba bean var. minor varieties for production under Northern European environmental conditions

The aim of the experiments was to evaluate a selection of faba bean (Vicia faba L.) var. minor varieties for further production improvement on the basis of their productivity and phenotype characteristics under the short season of the Northern European environmental conditions. The varieties evaluated were: Bauska, Favel, Fuego, Gloria, Jõgeva, Lielplatones, Priekulu and Priekulu viettejas. The highest and most stable average yield for 2015–2016 years was recorded in Bauska and Priekulu, with 3.77 and 3.64?t/ha, respectively. The incidence of chocolate spot and rust was in low to middling. Plant average height for 2015–2016 years was greatest in Bauska, Lielplatones and Priekulu vietejas, with 107.4, 110.7 and 110.0?cm, respectively. Resistance to lodging was best in Bauska and Fuego. From these yield and phenotype characteristics results we conclude that Lielplatones is the most suitable faba bean var. minor varieties for breeding in Northern European conditions, because of the following characteristics: middle yielding, quite high content of protein, very small seeds, low susceptibility to chocolate spot, good resistance to lodging. Thus almost every tested variety had some very good characteristics, which may also be valuable for the breeding of new varieties.     

The effect of the annual use of pesticides on soil microorganisms,pesticide residues in the soil and barley yields

A study has been made of the influence of pesticides used annually on soil microorganisms and crop yields. The persistence of these pesticides in the soil was also investigated. The herbicides MCPA, glyphosate, maleic hydrazide and tri-allate, and the insecticide parathion, were applied on experimental plots on which barley was grown during the years 1973-1981. The fungicide 2-methoxyethylmercury chloride was used every year for dressing the seeds grown in pesticide-treated plots. The pesticide treatments did not affect significantly the numbers of several groups of soil microorganisms. A slight increase was, however, observed in the nitrification activity in the soil. The barley yields were on average higher on pesticide-treated plots than on controls because of successful weed control. Pesticide residues in the soil were generally very low; for example, for parathion they were below 0.02 mg kg^?1 within 11 days, and for MCPA 0.06 mg kg^?1 within 7 days. However, the glyphosate residue was 1.6 mg kg^?1 in the autumn 2 days after the treatment, and the residue settled to a level of 0.2 mg kg^?1 during the following summer. No clear dependence was observed between the residue level and the time between treatment and sampling.