EROZIJA TLA VODOM U UZGOJU RAZLICITIH USJEVA PRI RAZLICITIM ZAHVATIMA OBRADE NA PSEUDOGLEJU SREDISNJE HRVATSKE

Water erosion was recorded during a four-year period (1994-1998.) on Luvic stagnosol (pseudogley), in the Daruvar area (Central Croatia), in different crop development stages according to USLE, under six tillage treatments in growing common arable crops in the common crop sequence. A much higher rate of erosion, higher than Soil loss tolerance (T value) was recorded in the growing of spring crops (row crops) than in winter crops of high plant density, where it was below the T value. In the growing of spring crops, the critical period with maximal water erosion was the period of seedbed preparation (SB period according of USLE), the period just after sowing. In the growing of maize and soybean, this is the period when over 80% of the overall annual erosion occurs in all tillage variants. As expected, the maximal rate of soil erosion, higher than the T value, was recorded in the standard plot according to USLE, followed by the variant of conventional up/down the slope tillage. Soil erosion was much smaller and below the T value in the no-tillage variant and in all variants with tillage across the slope. This means that these variants of soil tillage can be defined as conservation tillage in agroecological conditions of this part of Croatia. In growing winter crops of high density (wheat and oil seed rape), no critical periods were observed and erosion was much below the T value and was uniformly distributed throughout the whole growing season. According to the results, to reduce soil erosion below the T value on slopes of inclination higher than 9%, soil conservation practices are all tillage operations across the slope and/or a reduced crop rotation, without row crops.Tijekom cetvorogodišnjeg razdoblja (1994-98) na pseudogleju središnje Hrvatske pri razlicitim varijantama obrade tla istraživana je erozija tla vodom. U istraživanja su ukljuceni usjevi koji dominiraju u ovom podneblju, dok su varijante obrade slijedece: 1. Standardna parcela prema USLE - crni ugar 2. Konvencionalno oranje (do 25 cm) uz i niz nagib 3. Izostavljanje obrade - izravna sjetva, 4. Konvencionalno oranje okomito na smjer nagiba 5. Vrlo duboko oranje (do 50 cm) okomito na smjer nagiba. 6. Podrivanje na 60 cm dubine + konvencionalno oranje okomito na smjer nagiba. Temeljem polucenih rezultata i odnosa s tolerantnom erozijom za ovaj tip tla zakljucujemo da su erozijski nanosi pri u uzgoju jarina rijetkog sklopa (kukuruz i soja) mnogo veci u odnosu na tolerantno odnošenja za ovaj tip tla. Kriticno razdoblje pri uzgoju ovih kultura je neposredno poslije sjetve ovih usjeva (razdoblje nicanja pa dok usjev nije prekrio 10% površine). U ovom razdoblju utvrdeno je preko 80 % ukupne godišnje erozije, bez obzira na smjer obrade. Pri uzgoju ozimih kultura gustog sklopa (pšenica i uljana repica) nisu zabilježeni kriticna razdoblja, dok je ukupna erozija izrazito niža od tolerantnog odnošenja, pa u obzir dolaze svi istraživani nacini obrade tla. Temeljem svega navedenog zakljucujemo da je obrada uz/niz nagib pri uzgoju jarina rijetkog sklopa visoko rizicna na nagnutim terenima, pa bi taj nacin obrade tla trebalo napustiti. Izostavljanje obrade i bilo koji od nacina obrade okomito na nagib preporucamo za širu primjenu u poljoprivrednoj proizvodnji. Smatramo da je rijec je o nacinima obrade tla koji su u skladu s održivom poljoprivredom u ovom podneblju

EROZIJA TLA VODOM U UZGOJU RAZLICITIH USJEVA PRI RAZLICITIM ZAHVATIMA OBRADE NA PSEUDOGLEJU SREDISNJE HRVATSKE

Water erosion was recorded during a four-year period (1994-1998.) on Luvic stagnosol (pseudogley), in the Daruvar area (Central Croatia), in different crop development stages according to USLE, under six tillage treatments in growing common arable crops in the common crop sequence. A much higher rate of erosion, higher than Soil loss tolerance (T value) was recorded in the growing of spring crops (row crops) than in winter crops of high plant density, where it was below the T value. In the growing of spring crops, the critical period with maximal water erosion was the period of seedbed preparation (SB period according of USLE), the period just after sowing. In the growing of maize and soybean, this is the period when over 80% of the overall annual erosion occurs in all tillage variants. As expected, the maximal rate of soil erosion, higher than the T value, was recorded in the standard plot according to USLE, followed by the variant of conventional up/down the slope tillage. Soil erosion was much smaller and below the T value in the no-tillage variant and in all variants with tillage across the slope. This means that these variants of soil tillage can be defined as conservation tillage in agroecological conditions of this part of Croatia. In growing winter crops of high density (wheat and oil seed rape), no critical periods were observed and erosion was much below the T value and was uniformly distributed throughout the whole growing season. According to the results, to reduce soil erosion below the T value on slopes of inclination higher than 9%, soil conservation practices are all tillage operations across the slope and/or a reduced crop rotation, without row crops.Tijekom cetvorogodišnjeg razdoblja (1994-98) na pseudogleju središnje Hrvatske pri razlicitim varijantama obrade tla istraživana je erozija tla vodom. U istraživanja su ukljuceni usjevi koji dominiraju u ovom podneblju, dok su varijante obrade slijedece: 1. Standardna parcela prema USLE - crni ugar 2. Konvencionalno oranje (do 25 cm) uz i niz nagib 3. Izostavljanje obrade - izravna sjetva, 4. Konvencionalno oranje okomito na smjer nagiba 5. Vrlo duboko oranje (do 50 cm) okomito na smjer nagiba. 6. Podrivanje na 60 cm dubine + konvencionalno oranje okomito na smjer nagiba. Temeljem polucenih rezultata i odnosa s tolerantnom erozijom za ovaj tip tla zakljucujemo da su erozijski nanosi pri u uzgoju jarina rijetkog sklopa (kukuruz i soja) mnogo veci u odnosu na tolerantno odnošenja za ovaj tip tla. Kriticno razdoblje pri uzgoju ovih kultura je neposredno poslije sjetve ovih usjeva (razdoblje nicanja pa dok usjev nije prekrio 10% površine). U ovom razdoblju utvrdeno je preko 80 % ukupne godišnje erozije, bez obzira na smjer obrade. Pri uzgoju ozimih kultura gustog sklopa (pšenica i uljana repica) nisu zabilježeni kriticna razdoblja, dok je ukupna erozija izrazito niža od tolerantnog odnošenja, pa u obzir dolaze svi istraživani nacini obrade tla. Temeljem svega navedenog zakljucujemo da je obrada uz/niz nagib pri uzgoju jarina rijetkog sklopa visoko rizicna na nagnutim terenima, pa bi taj nacin obrade tla trebalo napustiti. Izostavljanje obrade i bilo koji od nacina obrade okomito na nagib preporucamo za širu primjenu u poljoprivrednoj proizvodnji. Smatramo da je rijec je o nacinima obrade tla koji su u skladu s održivom poljoprivredom u ovom podneblju

INFLUENCE OF TILLAGE ON SOIL PROPERTIES, YIELD, AND FAT AND PROTEIN CONTENT IN THE GRAIN OF MAIZE

Na pokušalištu Visokog gospodarskog učilišta u Križevcima tijekom 2008. godine istraživan je utjecaj različitih načina obrade na značajke tla i prinose zrna kukukuruza (Zea mays L.). Uz navedeno, istraživan je utjecaj obrade i značajki tla na ukupni sadržaj masti i bjelančevina u zrnu kukuruza. Uglavnom je utvrđen povoljniji utjecaj reducirane obrade na fizikalne značajke tla u odnosu na intenzivnije načine obrade s više zahvata. Kod svih istraživanih načina obrade tla ustanovljeni su pozitivni korelacijski odnosi između sadržaja ukupnih masti, bjelančevina i kapaciteta tla za vodu. Najveći korelacijski koeficijent utvrđen je za bjelančevine kod varijante B (r = 0,51; p < 0,05), a za ukupni sadržaj masti kod varijante E (r = 0,56; p < 0,05). Veće vrijednosti kapaciteta tla za zrak također su utjecale na veći sadržaj ukupnih masti (signifikantno kod varijante D s vrijednošću r = 0,65; p < 0,01) i bjelančevina (signifikantno kod varijante D s vrijednošću r = 0,63; p < 0,01). Utvrđen je također nepovoljan utjecaj zbijenosti tla na sadržaj ukupnih masti (signifikantno kod varijante D s vrijednošću r = - 0,77; p < 0,001) i bjelančevina (signifikantno kod varijante D s vrijednošću r = - 0,51; p < 0,05) kod svih istraživanih načina obrade tla. Signifikantno manje vrijednosti sadržaja humusa u tlu bile su kod varijante E (intenzivnija obrada) u odnosu na ostale istraživane načine obrade tla, osim u odnosu na varijantu B (p < 0,05), a glede ukupnog sadržaja dušika u tlu statistički opravdanih razlika nije bilo. Također su utvrđeni pozitivni korelacijski odnosi između sadržaja bjelančevina i količine humusa u tlu (signifikantno kod varijante B; r = 0,73; p 0,05). Slični korelacijski odnosi dobiveni su između sadržaja ukupnih masti u zrnu i ukupnog sadržaja dušika (p> 0,05). Većinom su utvrđeni negativni korelacijski odnosi između ostvarenih prinosa i sadržaja bjelančevina u zrnu, a također je dobiven najveći negativni korelacijski koeficijent između ukupnog sadržaja masti u zrnu i prinosa (p >0,05). Signifikantno niži prinosi zrna kukuruza bili su na varijanti A (reducirana obrada) u odnosu na ostale istraživane načine obrade tla (p < 0,05).The influence of different tillage systems on soil properties and yields of maize grain (Zea mays L.) was investigated during 2008 on the experimental field of the College of agriculture in Križevci. The influence of tillage and soil properties on total fat and protein content in maize grain was also investigated. Mainly more positive effect of reduced tillage on physical soil properties was determined compared to more intensive systems of tillage. Positive correlations between fat and protein content and water capacity of soil were determined for all investigated tillage systems. The highest correlation coefficient was determined for protein content in tillage system B (r = 0.51; p<0.05), and for total fat content in system E (r = 0.56; p < 0.05). The higher values of soil air capacity also influenced a higher total fats content (significant for tillage variant D with the value r = 0.65; p < 0.01) and also a higher protein content (significant for tillage variant D with the value r = 0.63; p < 0.01). A negative impact of soil compactness on total fat content was also determined (significant for D variant with the value r = -0.77; p < 0.001) and on protein content (significant for D variant with the value r = -0.51; p < 0.05) for almost all investigated tillage systems. Significantly lower values of humus content in the soil were registered for E variant (more intensive way of tillage) compared to other variants of tillage, except in relation to variant B (p < 0.05), while there were no significant differences between tillage systems related to total nitrogen content in the soil. Positive correlations were determined between protein content and amount of humus in the soil (significant for B variant; r = 0.73; p 0.05). Similar correlations were determined between fat and nitrogen in maize grain (p > 0.05). Mostly negative correlations weredetermined between yields gained and content proteins in maize grain, and the highest negative correlation coefficient was determined between total fat content in maize grain and yields of maize grain (p > 0.05). Significantly lower yields of maize grain were determined for variant A (reduced tillage) compared to other investigated variants of tillage (p < 0.05)

WATER EROSION IN DIFFERENT CROP DEVELOPMENT STAGES AND TILLAGE PRACTICES ON LUVIC STAGNOSOL OF CENTRAL CROATIA

Water erosion was recorded during a four-year period (1994-1998.) on Luvic stagnosol (pseudogley), in the Daruvar area (Central Croatia), in different crop development stages according to USLE, under six tillage treatments in growing common arable crops in the common crop sequence. A much higher rate of erosion, higher than Soil loss tolerance (T value) was recorded in the growing of spring crops (row crops) than in winter crops of high plant density, where it was below the T value. In the growing of spring crops, the critical period with maximal water erosion was the period of seedbed preparation (SB period according of USLE), the period just after sowing. In the growing of maize and soybean, this is the period when over 80% of the overall annual erosion occurs in all tillage variants. As expected, the maximal rate of soil erosion, higher than the T value, was recorded in the standard plot according to USLE, followed by the variant of conventional up/down the slope tillage. Soil erosion was much smaller and below the T value in the no-tillage variant and in all variants with tillage across the slope. This means that these variants of soil tillage can be defined as conservation tillage in agroecological conditions of this part of Croatia. In growing winter crops of high density (wheat and oil seed rape), no critical periods were observed and erosion was much below the T value and was uniformly distributed throughout the whole growing season. According to the results, to reduce soil erosion below the T value on slopes of inclination higher than 9%, soil conservation practices are all tillage operations across the slope and/or a reduced crop rotation, without row crops

The concentration of adrenaline and noradrenaline in the serum of dogs under the influence of calcium channels blockers

The most important characteristic of calcium channels is selective regulation of slow incoming stream of calcium into the cell tissue providing the slow increasement of action potential. Such tissues include smooth muscles of blood vessels, cardiocytes and heart noduses (AV and SA node). Different calcium antagonists have different effects on previous tissues due to their different chemical formula. Verapamile, Nifedipin and Diltiazem are the most frequently used of all. Their commonest characteristic is blocking the calcium channels causing vasodilatation of blood vessels as well as negative inotropic and chronotropic influence. By blocking the incoming calcium through slow channels of myofibrils of smooth muscles, the antagonists of calcium decrease the quantity of available calcium for contraction which causes vasodilatation. The most famous and most frequently used calcium antagonist is Verapamile. In terms of electrophysiology, Verapamile inhibits action potentials of heart noduses, especially the AV node, where the slow incoming of calcium is the most important for depolarization. Prolongation of the efective refractory period of SA node causes the heart frequency decreasement while prolongation of the effective refractory period of AV node slows down the work of chambers in case of flater and fibrillation of atriums. The molecules of calcium-bonding protein called kalmodulin are located in synaptic endings. Each kalmodulin can bond four calcium ions providing transfer into active calcium-kalmodulin complex which activates the kinase protein. Activated kinase protein starts the exocytosis of neurotransmitters into synaptic gap. Apart from activating kinase protein, calcium-kalmodulin complex also starts the activity of calcium pump presynaptic membrane which pumps calcium out of presynaptic ending stopping the further exocytosis of neurotransmitters into synaptic gap. Taking into consideration the fact that opening the calcium channels on membrane of presynaptic ending is necessary to free the neurotransmitter out of the vesicle, the aim of our work is to study whether Verapamile has effects on the membrane of presynaptic endings of sympathetic nervous system checking the level of catecholamine in serum. The experiment was conducted in 6 healthy dogs which were, after 10-minute-infusion (0.9% NaCl), treated with intravenous bolus veramapile injections in three occasions, in every 5 minutes, until the first signs of intoxication had appeared. This caused bradycardia, heart rhythm disorder and blood pressure drop. In order to determine the level of catecholamine, blood was taken sequentially, in every 5 minutes, before the new dose of verapamile was given. Verapamile (given intravenous) significantly decreases the concentration of adrenaline and noradrenaline in the serum of dogs

Serum myeloperoxidase chlorinating activity in acute ischemic stroke

Beyond traditional risk factors, inflammation is believed to play a role in the development of ischemic stroke (IS). During inflammation neutrophil leukocytes degranulate, thereby releasing the enzyme myeloperoxidase (MPO) into extracellular space. In addition to peroxidase activity, MPO expresses also a chlorinating activity, and catalyzes the formation of hypochlorous acid and long-lived oxidants - chloramines. In this study we assessed serum chlorinating MPO activity and concentration of total chloramines. We included 29 patients with acute IS, aged 69.0 years (64.2 - 78.0) and 25 control subjects without IS, aged 69.0 years (67.0 - 72.0). It was found that neutrophil cell count was higher in IS than in controls (4.56 ± 1.76 vs. 7.74 ± 3.35 × 109/L, in control and IS group, respectively; p< 0.05). Serum chlorinating MPO activity was also higher in IS group than in controls (67.2 U/L vs. 92.3 U/L, in controls and in patients, respectively; p < 0.05). Concentration of total chloramines was higher in IS group than in controls, but the difference did not reach statistical significance (p=0.178). MPO activity was significantly correlated with serum triglycerides (p<0.05). There was no statistically significant correlation between chlorinating MPO activity and chloramines (p=0.402), while correlations between MPO activity and neutrophil cell count (p=0.071), and MPO activity and the presence of arrhythmia (p=0.094) were both of borderline significance. These results indicate that MPO may be implicated in pathogenesis of IMU, which could be partly due to chlorination of biologically important molecules within vascular compartment