Genetically modified (GM) rice (LibertyLink, event LLRICE62) that is tolerant to glufosinate ammonium (Liberty) herbicide was compared with a near-isogenic (NI) conventional medium-grain brown rice (cultivar, Bengal) and a commercially milled long-grain brown rice in diets for growing-finishing pigs. The GM and NI rice were grown in 2000. The GM rice was from fields treated (GM+) or not treated (GM-) with glufosinate herbicide. The GM- and NI rice were grown using herbicide regimens typical of southern United States rice production practices. The four rice grains were similar in composition. Growing-finishing pigs (n = 96) were fed fortified rice-soybean meal diets containing the four different rice grains from 25 to 106 kg BW. Diets contained 0.99% lysine initially (growing phase), with lysine decreased to 0.80% (early finishing phase) and 0.65% (late finishing phase), when pigs reached 51 and 77 kg, respectively. The percentage of rice in the four diets was constant during each of the three phases (72.8, 80.0, and 85.8% for the growing, early-finishing, and late-finishing phases, respectively). There were six pen replicates (three pens of barrows and three pens of gilts) and four pigs per pen for each dietary treatment. All pigs were slaughtered at the termination of the study to collect carcass data. At the end of the 98-d experiment, BW gain, feed intake (as-fed basis), and feed:gain ratio did not differ (P > 0.05) for pigs fed the GM+ vs. conventional rice diets, but growth performance traits of pigs fed the GM+ rice diets were superior (P < 0.05) to those of pigs fed the GM- rice diet (ADG = 0.86, 0.79, 0.81, and 0.85 kg/d; ADFI = 2.41, 2.49, 2.37, and 2.45 kg/d; feed:gain = 2.80, 3.17, 2.95, and 2.89 for GM+, GM-, NI, and commercially milled rice, respectively). Carcass traits (adjusted for final BW) did not differ (P = 0.10) among treatments (hot carcass yield = 73.5, 72.6, 72.6, and 73.2%; 10th-rib backfat = 23.0, 22.7, 21.3, and 23.8 mm; LM area = 38.6, 38.0, 38.2, and 38.1 cm(2); carcass fat-free lean = 50.5, 50.5, 51.2, and 50.0%). Gilts grew slower (P < 0.05) and were leaner (P < 0.05) than barrows. Responses to type of rice did not differ between barrows and gilts, with no evidence of a diet x gender interaction (P = 0.50) for any trait. The results indicate that the glufosinate herbicide-tolerant rice was similar in composition and nutritional value to conventional rice for growing-finishing pigs.
ABSTRACT:To keep forest soils fertile, forest practitioners plant mixed stands that are composed of both economically efficient trees such as conifers and soil-improving broadleaves. This is a mandated practice in the Czech Republic. As the new forest grows, it creates a dense canopy. The canopy is a principal source of organic matter to the forest soil. The formation of new forest humus is particularly important in first-generation forests on the former agricultural soil. Former meadow is a suitable site for forest floor and soil investigation since forest-floor humus covering the surface of the soil is a completely new layer. Both pure evergreen conifer and mixed treatments were planted in 2001. The experimental plot was established in order to investigate performance of tree species and restoration of forest-site conditions. We sampled dead-plant material and 0-10 cm topsoil to investigate their properties under the 10-year-old stands. We compared the treatments by descriptive statistics using both univariate and multivariate techniques. Dry mass (medians of weight) varied among the treatments from 11 to 19 Mg·ha -1 . The forest floor nutrient concentrations appeared to be dependent on the presence of admixed deciduous tree species (sycamore maple, small-leaved linden and European larch) as these forest floors (EL1, EL2, NS3, SM) were higher in base cations and phosphorus compared to pure spruce (NS1, NS2) and pure Douglas fir (DF) treatments. The first axis of PCA ordination plot revealed 45% of total variability and showed a clear distinction between evergreen coniferous and mixed species treatments. Young plantations produced forest floors of different quality; however it was not reflected in the topsoil properties.
ABSTRACT:The effect of stand density on the resistance of Scots pine (Pinus sylvestris L.) to climatic stress and subsequent response of diameter increment were investigated using data gathered from six long-term experimental series located in the typical pine regions of the Czech Republic (sandy nutrient-poor soils on the Pineto-Quercetum oligotrophicum-arenosum). Diameter growth of dominant individuals (with the largest diameter at the age before the first thinning) was measured in all variants of experimental series (control and thinned). Monthly average temperature and total precipitation were taken from the nearest climatological stations and, additionally, three climatic factors (precipitation and temperature ratio in different periods) were calculated. Diameter growth responses were analyzed in connection with long-term deviations of climatic characteristics. The effect of different stand density on diameter growth response in relation to climate situations was evaluated by cluster analysis and the variability of diameter growth response to climate situations was interpreted by the variance of correlation coefficients in groups of sample trees. The investigation confirmed the significant negative effect of meteorological drought on diameter increment of studied pine stands in the period of the last 30 years. At the same time, we observed a significant positive influence of higher spring (February, March) air temperatures on the annual diameter growth of dominant trees. The effect of stand density (in thinned stands) on the relation between diameter growth and climatic characteristic was not significant.
Litterfall, an important component of the nutrient cycle in forest ecosystems, was measured for 9 years in young oak stands on two localities classified as beech-oak climax (Fageto-Quercetum). We estimated that about 4 Mg of dry mass per hectare fell each year. Nutrient content in the litterfall represents annually per hectare approximately 40-55 kg of nitrogen, 2-3 kg of phosphorus, 7-16 kg of potassium, 41-73 kg of calcium and 6-7 kg of magnesium. The amount of litterfall is positively correlated with stand basal area and with the death of suppressed tress with small crowns. We found a positive correlation between annual litterfall and the sum of precipitation and a negative correlation between annual litterfall and temperature in summer.
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