Kovac L.,Research Institute of Agroecology |
Jakubova J.,Research Institute of Agroecology |
Sarikova D.,Research Institute of Agroecology
Agriculture | Year: 2014
Experiments with soybean on heavy soils of East Slovak Lowlands were established in the years 2010-2012. The effect of mineral fertilisers and soil conditioner application on soybean's yield using three tillage systems (minimum tillage (MT), conventional tillage (CT) and no tillage (NT)) was studied. Production costs and economic efficiency of crop management practices were evaluated. The influence of production year on soybean crop was significant in the order of 2011, 2010 and 2012. Statistical evaluation confirmed that the effects of CT and MT systems were more significant compared with NT system. No significant differences were found between the variants of the mineral fertiliser and conditioner application. Differences in the total cost of soybean cultivation, as measured between years, were not significant. Fertilisation variants with application of HUMAC agro and NPK generated the highest costs. On the other hand, the lowest costs were achieved at fertilisation variants with application of NPK alone. Comparing tillage variants, the CT system had the highest costs each year. Significant savings were achieved on MT and NT variants. During the experimental period, a profit was reached on all variants. Applying NPK alone, the highest profit was achieved in 2010 and 2012 using MT system and in 2011 with CT tillage. The variant b2 with PRP sol in the years 2010 and 2011 was the most profitable using NT system and in 2012 using MT. Variant with HUMAC agro was the most profitable in each year using MT. The lowest income threshold for zero profitability was calculated in 2012. Using CT farming techniques at NPK fertilisation variant b1 in 2012, the income threshold was 1.85 t/ha, at variant b2 PRP sol it was 2.10 t/ha and at variant b3 HUMAC agro it was 2.42 t/ha. At MT and NT systems, the income threshold values for zero profitability were lower. © 2014 Ladislav Kováč et. al. 2014.
Fecak P.,Research Institute of Agroecology |
Sarikova D.,Research Institute of Agroecology |
Cerny I.,Slovak University of Agriculture
Plant, Soil and Environment | Year: 2010
This field polyfactorial trial with soybean was performed on gleyey alluvial soil in 2006-2008. Three tillage systems: conventional, reduced (spring shallow cultivation to a depth of 100 mm followed by drilling), no-tillage and two doses of starting N: 50 kg N/ha, 25 kg N/ha were tested in this trial. The trial was organized in a complete randomized block design with four replicates. All data were subjected to ANOVA, LSD method and regression analysis using Statgraphics. Seed yield was highly significantly (P ≤ 0.01) affected by weather conditions. Weather was the most dominant factor that influenced seed yield. The highest average yield was found in 2008 - 2.77 t/ha, followed by 2.34 t/ha in 2006 and the lowest yield of 1.98 t/ha in 2007. The stage of seed-filling was found as the most sensitive to water stress resulting in a yield reduction. Seed protein and oil were also highly significantly (P ≤ 0.01) affected by weather. This influence, as compared with tillage system and starting N, was much higher. A negative correlation coefficient r = -0.96 was found between protein and precipitation, compared to a positive correlation coefficient r = 0.81 between oil and precipitation. Tillage system affected seed yield highly significantly (P ≤ 0.01). The highest average yield of 2.60 t/ha gave conventional tillage, followed by reduced tillage - 2.39 t/ha and no-tillage - 2.11 t/ha. The results do not support the choice of no-tillage for profitable soybean production on heavy soils. Starting N fertilization had a significant (P ≤ 0.05) influence on seed yield. The average yield difference between the two starting N treatments was 0.05 t/ha in favour of the dose of 25 kg N/ha. This dose was proven as a rational one.