Birdsfoot trefoil is a perennial legume for the production of high-quality forage. Improving the production and quality of forage is one of the strategic objectives of breeding programs. The genotypes for this trial were selected from promising offspring collected from local populations in Bosnia and Herzegovina. A trial with eight genotypes (7 promising lines and 1 variety) was designed in a randomized block system with four replicates. In the first growth, 11 components of yield and quality of biomass were analyzed, and in the second growth, four additional parameters for seed production. In the first growth, highly significant correlations were found between plant height and the proportion of leaves (0.85**) and the yield of green matter and dry matter (0.81**), while a high negative correlation was found between the nitrogen-free extract (NFE) and the crude protein content (-0.79**). In the regrowth, statistically highly significant (p<0.01) positive correlations were found between the content of NFE and ash (0.77**). Statistically significant (p<0.05) positive relationships were found between green matter yield and dry matter yield (0.81**), green matter yield and stem diameter (0.79*), seed yield and number of pods (0.83*), and cellulose content and plant height (0.73*). The identification of positive correlations for certain productive and nutritional traits will be used in breeding programs for the creation of new varieties with improved forage quality.

This paper presents the results of a two-year study of six selected soybean genotypes with the aim of examining which of the genotypes in the given production conditions give the best results in regards with the amount and quality of seed yield. All genotypes belong to a zero-maturity group. The correlation between the grain yield per plant and other studied traits was tested through linear (simple) correlations. The testing showed that the following traits had a positive highly significant impact on seed yield: the number of seeds per plant (0.917**), seed germination energy (0.897**), seed moisture content (0.803**), plant height (0.802**), seed germination (0.789**), the number of seeds in pods (0.696**), the number of harvested plants per m-2 (0.590**), the number of plants (phenophase 1-3 in the three-leaf stage) per m2 (0.550**), 1000 seed mass (0.471**), and the height to the first node (0.412**).

The field experiment of liming (0 and 10 t ha-1 of powdered hydrated lime) and phosphorus (P) fertilization (monoammonium phosphate or MAP: 12% N + 52% P2O5) started in autumn 2008 on acid soil of Laktasi municipality (Republic of Srpska, Bosnia and Herzegovina). Three doses of P (0, 500, 1000 and 1500 kg P2O5 ha -1) on ordinary fertilization were applied. The experiment was conducted in four replicates. Basic plots of liming and P fertilization were 640 m2 and 40 m2, respectively. Maize was grown in monoculture. Under drought stress of 2011 and 2012 yields were considerably lower (mean 3.86 t ha-1) than in the remaining two years (mean 9.20 t ha-1). As affected by drought and high air-temperature, particularly in August, the 2012 growing season was especially unfavorable for maize growth because mean yield in the experiment was only 2.06 t ha-1 or 22% of yield realized in the 2010 growing season. As affected by liming yield of maize was increased by 31% (4-year mean), while P effect was considerably lower (6.14 and 6.65 t ha-1, for the control and average of ameliorative P treatments, respectively).

Different types of nutritional unbalances, including also low levels of plant available phosphorus (P), are often limiting factor of soil fertility in Croatia and in countries of the region, particularly in Bosnia and Herzegovina (B&H). Aim of this study was survey our recent investigations (eight stationary field experiments) of maize, soybean, wheat and barley responses to ameliorative P fertilization up to different levels (depending on the trial up to from 825 to 1580 kg P2O5 ha-1). Either MAP (monammonium phosphate: 12% N + 52% P2O5) or triplephosphate (45% P2O5) were used as source of P. Selection of soil was made based on the previous soil test. In spite of low levels of available P (ammonium lactate method: below 10 mg P2O5 100 g-1 of soil), response of the field crops to applied fertilization in four experiments in Croatia was mainly moderate or without significant differences. However, in B&H by using the rate of 1580 kg P2O5 ha-1 maize yields were increased depending on year in municipality Kozarska Dubica from 16 to 40%, Gradiska from 8 to 38%, and in Laktasi from 6 to 18% Also, by using 975 kg P2O5 ha-1 soybean yield in Odzak municipality was increased for 20%. In general, year effect (weather characteristics) was the most influencing factor of yields in our investigations. We presume that ammonium-lactate method is not suitable as criterion of P supplies in all tested soils. From other side, majority of tested soils have additional soil fertility limitations as low pH or unfavorable physical properties

INTRODUCTION Acid reaction and nutritional unbalances, mainly low level of plant available phosphorus (P) as well as unfavorable physical properties are limiting factor of soil fertility in Bosnia (Okiljevic et al., 1997; Resulovic and Custovic, 2002). It is estimated that about 25% of agricultural land of Bosnia and Herzegovina are pseudogley or similar soils (Markovic and Supic, 2003). P as a limiting factor of the field crop yield under conditions of the northwern Bosnia was object of survey article Markovic et al. (2006). Liming and increased fertilization (mainly with P) are usually recommendations for these soils improvement (Kovacevic et al., 2004, Petosic et al., 2003, Komljenovic et al., 2006, 2008). Aim of this study was testing maize response to ameliorative P fertilization on acid hydromorphic soil in Bosnian Posavina (Sava river valley) area.

Na kiselom tlu (pH u 1n KCl = 4, 32) kod Kozarske Dubice (lokalitet Brekinja) postavljen je 14. marta 2008. poljski pokus kalcizacije hidratnim krecom (kalcit : 73% CaO + 2-3% MgO + 21% vezane vode ; proizvođac Kamen Sirac d.d., Sirac, Hrvatska) u kolicinama 0 (kontrola), 15 t/ha, 30 t/ha i 45 t/ha. Pokus je postavljen prostorno u dva ponavljanja (osnovna parcela 50 m2), a svako od njih podijeljeno je na dvije parcelice kako bi se dobilo cetiri ponavljanja. Kukuruz (hibrid OsSK444) posijan je 18. aprila 2008.g pneumatskom sijacicom na planirani sklop 51021 biljaka/ha. Za gnojidbu kukuruza unijeto je u tlo (kg/ha) predsjetveno 400 kg NPK 7:20:30 i 100 kg uree (46% N), a obavljena je i jedna prihrana u fazi 5-6 listova kukuruza primjenom 200 kg KAN-a (27% N + 4, 8% MgO). Tako je ukupan fond hraniva dodan gnojidbom iznosio (kg/ha) 128 N + 80 P2O5 i 120 K2O. Kukuruz je obran rucno 11. oktobra 2008. g. Sa svake parcelice je uzet list ispod klipa u fazi svilanja (12. 07. 2008.), te u zriobi obrano dva puta po po dva srednja reda dužine 9 m. Masa klipa je izvagana elektronskom vagom (d = 100 g). Randman (udjel zrna u masi klipa) i vlaga zrna određeni su iz prosjecnog uzorka od 10 klipova. Ukupno 16 prosjecnih uzoraka lista ispod Ovisno o kolicini primjenjenog kreca, prinosi kukuruza su povecani prema kontroli (ostvareni prinos 7, 79 t/ha) za 10% (tretman 15 t/ha), 17% (30 t/ha), odnosno za 24% (45 t/ha). Vlaga zrna u trenutku berbe kukuruza bila je prosjecno 21, 0% i slicna na svim tretmanima. Kalcizacijom su signifikantno povecane koncentracije N u listu s 1, 59% N (kontrola) do 2, 57 % N, zatim P s 0, 17 % P do 0, 24 % P, dok su koncentracije K bile neovisne o kalcizaciji. Na kontroli je evidentiran nedostatak N (1, 57 % N) i niska koncentracija P (0, 17 % P), dok su na tretmanima kalcizacije koncentracije N bile niske (prosjek 2, 38 % N), a P je presao prag niske opskrbljenosti (prosjek 0, 24 % P). Koncentracije K bile su na svim tretmanima relativno skromne (prosjek 1, 60 % K), ali ipak u rangu dovoljne opskrbljenosti ovim elementom (iznad 1, 5 % K). Kalcizacija se preporucuje kao korisna mjera za povecanje prinosa i boljeg iskoristenja dusika i fosfora iz tla.