Fresh Matter Yield Research Articles

A Long-Run Reflections on Sustainable Development Policies and Solutions

The aim of the study was the assessment of productivity of maize and sorghum in depend on cultivation method and fertilizer dose cropped in ecological system. The study was conducted at the Institute of Soil Science and Plant Cultivation - Agricultural Experimental Station GrabA³w [Poland]. The first order factor was cultivation method and the second factor were composted manure dose. The study showed that the use of mechanical weed control in the cultivation of maize and sorghum resulted in a significant increase in the fresh matter yield compared to the control treatment. Increasing composted manure dose positively affected the yield of both plant species. The yield of fresh matter of maize fertilized with a dose of 20t ha-1 in the treatment without weed control, was by about 15% lower than yield of maize fertilized with a twice higher manure dose.

Ecotoxicological Properties of Tulipalin A-Based Superabsorbents versus Conventional Superabsorbent Hydrogels

The Phytotoxicological Aspects of a Novel Superabsorbent/Hydrogels: poly(acrylamide-co-sodium 4-hydroxy-2-methylenebutanoate), prepared from renewable monomer Tulipalin A, on the growth and development of monocotyledonousAvena sativaand dicotyledonousRaphanus sativus, was investigated and compared with the effect of borate-crosslinked poly(vinyl alcohol), poly(acrylamide), and poly(acrylamide-co-sodium acrylate) conventional hydrogels. Tulipalin A-based superabsorbent hydrogels revealed superior properties in terms of the combination of the tested properties. The results confirmed excellent suitability of Tulipalin A-based hydrogels for application as reservoirs of water during plant stress condition. Values of fresh matter (yield) and shoot height of the examined plants growing in soil amended with these hydrogels were ca 10% higher than those of plants growing in soil without hydrogels. Reference borate-crosslinked PVA hydrogels (containing increasing amount of borax cross-linker) revealed harmful effect on plants. The negative effect was observed on most of the investigated properties, increasing with content of the hydrogel in soil and concentration of the borax in it.

Biochar application and wastewater irrigation in urban vegetable production of Ouagadougou, Burkina Faso

In West Africa population growth and fast urbanization challenge food security for which urban and peri-urban agriculture plays an increasing role. Adding biochar to soils depleted in soil organic carbon may improve soil quality but its effectiveness in high input systems, such as urban horticulture in West Africa, is unknown. We studied the effects of fertilization, amended biochar from agricultural waste, irrigation water quality and quantity on small-scale urban vegetable production in a multi-factorial split-plot experiment on a Haplic Lixisol in Ouagadougou, Burkina Faso. A single application of corn cob biochar at the rate of 20 t ha−1 was used in a 2-year study covering eleven cropping cycles. Biochar significantly improved total fresh matter yields of two amaranth cycles by 39% and 17%, lettuce by 7% and carrot by 11%. Repeated measures analysis showed that biochar increased average total biomass by 9% and marketable yield by 6%. Biochar was effective on fertilized plots while plant growth on unfertilized plots was limited by nutrients, most likely nitrogen (N). A 33% reduction in irrigation water caused yield declines of 4–23% which was more pronounced in fertilized plots with higher water consumption by the larger plants. Biochar increased potassium (K) concentrations while wastewater reduced phosphorus (P) in plant tissue. The study showed a positive effect of biochar on crop yields and nutrition while wastewater effects were limited to nutrient deficient plots.

Effect of Dicamba and Adjuvant Combination on Parthenium Control, Fodder Yield and Yield Components of Forage Sorghum (Sorghum bicolor)

ABSTRACT: Parthenium is an important weed which poses severe threats to yield and quality of sorghum and many other summer season crops, worldwide. As in other field crops, parthenium also reduces yield and quality of forage plants in forage crops so it should be controlled in forage and fodder crops. Parthenium control efficacy of five herbicide treatments (including dicamba at 304.5 g a.i. ha-1 (full rate) alone, dicamba at full rate + 1% ammonium sulphate, dicamba at full rate + 2% ammonium sulphate, dicamba at 75% rate + 1% ammonium sulphate and dicamba at 75% rate + 2% ammonium sulphate) was tested in field trials for two consecutive years (2013 and 2014). One manual hoeing three weeks after crop emergence was also performed as a treatment and weedy check was kept as control. Application of the full rate of dicamba with 2% ammonium sulphate showed the lowest parthenium dry weight (16.5 g m-2 and 23.5 g m-2) and NPK uptake that seem to be due to the highest parthenium control efficiency of 79.6% and 73.8% during 2013 and 2014, respectively. This weed management strategy also gave maximum values of yield components of forage sorghum, including plant height (261 and 254 cm), stem diameter (0.97 and 0.84 cm), leaf area per plant (3,072 and 3,041 cm2), fresh fodder yield (63.4 and 60.9 t ha-1) and dry matter yield (17.4 and 15.8 t ha-1) in 2013 and 2014, respectively. Highest net return and marginal rate of return (346 and 356% in 2013 and 2014, respectively) were also found when the full rate of dicamba with 2% ammonium sulphate was applied. In conclusion, tank-mixed application of dicamba at 304.5 g a.i. ha-1 with 2% of ammonium sulphate proved to be better for efficient control of parthenium weed in forage sorghum.

Effects of sheep kraal manure on growth, dry matter yield and leaf nutrient composition of a local <i>Amaranthus</i> accession in the central region of the Eastern Cape Province, South Africa

Indigenous vegetables that supply abundant amounts of protein, vitamins, calories and minerals could alleviate problems of malnutrition, in developing countries. Amaranthus is one such vegetable that could be domesticated and cultivated but information on its fertility requirements is scanty. A dry-land field experiment was therefore conducted to study the effects of sheep kraal manure application rates on growth, fresh and dry matter yields, nutrient uptake and grain yield of one of the Amaranthus accessions that grow in the wild in the Eastern Cape. The treatments were sheep kraal manure rates ranging from 0 to 10 t/ha and an NPK {2:3:4(30) + 0.5% Zn} fertiliser as a positive control at 150 kg/ha. Low manure rates (≤2.5 t/ha) resulted in plant heights and fresh matter yields which were comparable to those in the unfertilised control, whereas higher rates (5 and 10 t/ha) and NPK fertiliser gave greater plant heights and higher yields at both 30 and 60 days after transplant (DAT) (p<0.05). At 30 DAT, manure application rates of ≥2.5 t/ha and the NPK fertiliser treatment, produced greater shoot dry-matter yields (≥29.35 g/plant) than the unfertilised control (17.11 g/plant). Uptake of N and P in the leaves increased with increase in manure application rate with N uptake reaching a maximum of 308 mg N /plant at a manure rate of 2.5 t/ha which corresponded with the maximum dry matter yield of 45.97 g/plant. There was no effect of manure rate or fertiliser on residual soil N and Ca, whereas P, K, Mg and Zn were increased (p<0.005). The findings suggested that ≥2.5 t/ha sheep kraal manure could result in growth, nutrient uptake and yield comparable to 150 kg/ha NPK fertiliser for the Amaranthus accession used in this work.Keywords: Amaranthus accession, sheep manure, dry matter yield, nutrient composition, residual nutrients

Morphogenetic Studies of Some Genotypes of Onion (Allium cepa L.) In Jos, Nigeria

The improvement of the fresh bulb and the economic dry matter yields of onion is dependent on the morphogenetic variability and the interrelationships amongst morphological attributes which can be used to determine the quality or performance of the crop. This research was aimed to study the morphogenetic characteristics of ten genotypes of onion (Ares, Violet de Galmi, Red Creole, “Wase”, “Dan Zaria”, “Dan Garko”, “Dan Giyawa”, “Bahaushe”, “Bakana” and “Yar Aleiro”) in Jos, Plateau State. Using the seedlings raised in the nursery, the genotypes were laid out in a completely randomized design (CRD) with four replicates. Results showed that morphological attributes differed amongst the genotypes, except the number of leaves per plant, neck thickness and horizontal bulb diameter. The study concludes that morphological differences, which are responsible for differences in fresh bulb and dry matter yields, exist amongst the different genotypes of onion. These attributes could be used as selection indices in the improvement of the onion.

Productive and Nutritional Aspects of Tithonia diversifolia Fertilized With Biofertilizer and Irrigated

Little is known about the agronomic aspects of Mexican Sunflower (Tithonia diversifolia), in spite of its potential for multiple uses. In this study, we evaluated the effects of application rates of biofertilizer and irrigation on yield, growth, and leaf chlorophyll and nutrient content of Mexican Sunflower. In an experiment in the Brazilian semi-arid region, we used a 5 × 2 factorial arrangement, consisting of five application rates of biofertilizer (0, 40, 80, 120, and 160 m3 ha-1), with and without irrigation. The statistical design was randomized blocks with three replications. Irrigated plants of Mexican Sunflower had greater dry and fresh matter yields, greater height, and greater leaf area index and leaf contents of K, Zn, and B. However, the high concentration of bicarbonate in the irrigation water reduced the leaf contents of N, Ca, S, Fe, and Mn. The mean increase in the two cuttings obtained with the use of irrigation was 350% and 314% for fresh and dry matter, respectively. The increase in the biofertilizer application increased the leaf chlorophyll contents of irrigated plants; however, it did not result in production or nutritional gains. In regions with low availability of rainfall, irrigated cultivation of Mexican Sunflower is recommended.

Correlations between agronomic traits and path analysis for silage production in maize hybrids

ABSTRACT The aim of the current study is to estimate the correlation coefficients and the consequence of genotypic correlations on direct and indirect effects through path analysis between agronomic traits of maize hybrids used for silage production. Eight (8) topcross hybrids and seven (7) checks were analyzed in completely randomized blocks, with six replications, in two environments: Campos do Goytacazes and Itaocara counties – Rio de Janeiro State, in the crop year 2015/2016. The following agronomic traits were assessed: plant height, first ear height, culm diameter, number of ears, ear yield with straw at silage maturity, ear yield without straw at silage maturity, grain yield at silage maturity, grains ratio in the fresh matter and fresh matter yield. The highest correlation estimates were found between the variables ear yield without straw and grain yield, and between ear yield with straw and ear yield without straw, with magnitudes 0.95 and 0.92, respectively. The coefficient of determination was high, which indicates that the assessed components explain most of the existing variation in fresh matter yield. According to the path analysis, the trait showing the strongest direct effect on fresh matter yield was the ear yield with straw at silage maturity, in association with the high correlation (r = 0.91), which showed the possibility of achieving significant gains through indirect selection.

Adjustment of Biomass Yield to a Dry Matter Basis in Switchgrass Breeding: A Necessity or a Nuisance?

Increases in biomass yield of switchgrass (Panicum virgatum L.) have been achieved, but the rate of gain has been slow and would benefit from improved efficiency of selection methods. Dry matter (DM) determinations at the time of harvest are a traditional method to adjust fresh matter yield (FMY) to a DM basis. The purpose of this study was to determine if DM determinations in switchgrass yield evaluations are necessary or unnecessary. Data from 219 trial‐years of 11 published experiments were used to evaluate the value of DM adjustment. Heritability for FMY and dry biomass yield (DBY) were similar, and the genetic correlation between these two traits was >0.8 for 96.7% of the trial‐years. The direct effect of FMY on DBY was three to four times greater than the direct effect of DM concentration. Because DM determination requires a larger field crew at the time of harvest, the use of FMY as a selection criterion requires significantly less labor than DBY at harvest time. Tripling the number of families evaluated and eliminating the DM step would increase the expected genetic gain for DBY by 17%. However, decreasing the number of replicates per family while eliminating the DM step would undermine the gains in efficiency due to reduced heritability for FMY. Although the risk of using FMY is low, achieving this increase in efficiency requires a serious commitment to evaluating a very large number of replicated families in each generation, an effort that may be beyond the ability and scope of most breeding programs.

Valorization of Fish Waste Compost as a Fertilizer for Agricultural Use

The manuscript presents results of the evaluation of compost from fish waste (FW) as a fertilizer for agricultural use. A pot experiment was conducted to compare the effects of compost from FW on the yield and macro and microelemental composition of ice lettuce (Lactuca sativa L.). In addition, the phytotoxicity degree of the compost and compost effects on seed germination and primary root growth were determined with white mustard (Sinapis alba L.). Compost used in the study consisted of FW and pine bark. Results of the evaluation enable concluding that the compost from FW is non-phytotoxic, mature, stable, and suitable for use in agriculture. Its addition to soil caused an increase in fresh and dry matter yield of leaves of ice lettuce (L. sativa L.). Fertilization had a significant effect on increased contents of nitrogen, phosphorus, potassium, sodium, calcium, and magnesium in leaves of the test plant. The average accumulation of microelements in ice lettuce (L. sativa L.) grown in the soil fertilized with compost from FW followed the descending order Fe > Cu > Ni > Zn > Mn, respectively. Soil fertilization with compost from FW improved the K:(Mg + Ca), K:Mg and K:Ca ratios but, simultaneously, deteriorated the Ca:P ratio.Graphical

Genomic prediction applied to high-biomass sorghum for bioenergy production

The increasing cost of energy and finite oil and gas reserves have created a need to develop alternative fuels from renewable sources. Due to its abiotic stress tolerance and annual cultivation, high-biomass sorghum (Sorghum bicolor L. Moench) shows potential as a bioenergy crop. Genomic selection is a useful tool for accelerating genetic gains and could restructure plant breeding programs by enabling early selection and reducing breeding cycle duration. This work aimed at predicting breeding values via genomic selection models for 200 sorghum genotypes comprising landrace accessions and breeding lines from biomass and saccharine groups. These genotypes were divided into two sub-panels, according to breeding purpose. We evaluated the following phenotypic biomass traits: days to flowering, plant height, fresh and dry matter yield, and fiber, cellulose, hemicellulose, and lignin proportions. Genotyping by sequencing yielded more than 258,000 single-nucleotide polymorphism markers, which revealed population structure between subpanels. We then fitted and compared genomic selection models BayesA, BayesB, BayesCπ, BayesLasso, Bayes Ridge Regression and random regression best linear unbiased predictor. The resulting predictive abilities varied little between the different models, but substantially between traits. Different scenarios of prediction showed the potential of using genomic selection results between sub-panels and years, although the genotype by environment interaction negatively affected accuracies. Functional enrichment analyses performed with the marker-predicted effects suggested several interesting associations, with potential for revealing biological processes relevant to the studied quantitative traits. This work shows that genomic selection can be successfully applied in biomass sorghum breeding programs.

Impact of nutrient supply on the expression of genetic improvements of cereals and row crops – A case study using data from a long-term fertilization experiment in Germany

Abstract Impacts of nutrient supply and different cultivars (genotypes) on actual yield levels have been studied before, but the long-term response of yield trends is hardly known. We present the effects of 24 different fertilizer treatments on long-term yield trends (1953–2009) of winter wheat, winter rye, sugar beet and potato, with improved cultivars changing gradually over time. Data was obtained from the crop rotation within the long-term fertilization experiment at Dikopshof, Germany. Yield trends were derived as the slope regression estimates between adjusted yield means and polynomials of the first year of cultivation of each tested cultivar, when tested for more than two years. A linear trend fitted best all data and crops. Yields in highly fertilized treatments increased linearly, exceeding 0.08 t ha−1 a−1 for both, winter wheat and winter rye, and ≥0.30 and ≥0.20 t ha−1 a−1 for sugar beet and potato fresh matter yields. Yield trends of winter cereals and sugar beet increased over time at N rates ≥40 kg ha−1 a−1, being 0.04–0.10 t ha−1 a−1 for cereals and 0.26–0.34 t ha−1 a−1 for sugar beet, although N rates >80 kg ha−1 a−1 produced a stronger effect. Nitrogen was the most influential nutrient for realisation of the genetic yield potential. Additional supply of P and K had an effect on yield trends for rye and sugar beet, when N fertilization was also sufficient; high K rates benefited potato yield trends. We highlight the importance of adequate nutrient supply for maintaining yield progress to actually achieve the crop genetic yield potentials. The explicit consideration of the interaction between crop fertilization and genetic progress on a long-term basis is critical for understanding past and projecting future yield trends. Long-term fertilization experiments provide a suitable data source for such studies.

Ciclagem de nutrientes por plantas de cobertura de verão

The utilization of plant species for ground cover in order to supply nutrients and protect the soil is important for the sustainability of agricultural systems. The objective of this study was to evaluate the production of fresh and dry matter, and the content and accumulation of nutrients in summer cover crops. The experimental design was of randomized blocks, with seven treatments (sudan grass, crotalaria, jack beans, pigeon pea, buckwheat, velvet bean and fallow) and six replications. The parameters evaluated in the cover crops were the fresh and dry matter yield and the content and accumulation of macronutrients and micronutrients in the above-ground biomass of the plants. The highest levels of nutrients were obtained in the legume crops. The crotalaria and jack beans had both higher dry matter yield and accumulation of macronutrients and micronutrients.

Influence of plant density and hilling on yield and profitability of arrowroot1

ABSTRACT The global production of arrowroot is minimal, and this may be partially associated to the lack of standardized agronomic techniques for its commercial cultivation. This study aimed to assess the yield and profitability of arrowroot plants (‘Comum’ cultivar) grown using different plant spacings in the cropping row (20 cm, 25 cm, 30 cm and 35 cm) and a varying number of hilling applications (0, 1 and 2). The treatments were arranged in a 4 x 3 factorial scheme, in a randomized experimental block design, with six replications. After harvesting, the fresh and dry matter yields of leaves, rhizomes and roots were determined. Production costs and gross and net incomes were also calculated. The highest yields for fresh leaves (8.75 t ha-1), rhizomes (32.92 t ha-1) and roots (8.45 t ha-1) were obtained with a plant spacing of 20 cm. No interaction between the factors, neither significant differences for the use or not of hilling, were observed on the analyzed variables. The costs per hectare ranged from BRL 8,488.83 (35 cm without hilling) to BRL 10,376.23 (20 cm with two hillings). The highest yields and gross and net incomes were obtained with the spacing of 20 cm between plants.

Water use in agro-pastoral livelihood systems within the Bulgan River watershed of the Altay Mountains, Western Mongolia

Watersheds in the arid and semi-arid regions of Mongolia are especially vulnerable to the effects of climate and land cover change, which will likely exacerbate the disparity between water availability and demand. This study was conducted to analyse land cover changes between 1972 and 2013 and to characterize the currently prevailing livelihood strategies and farming practices in the river oasis Bulgan sum, Western Mongolia. The Soil and Water Assessment Tool (SWAT) was used to simulate the water-use efficiency for the concerned Bulgan River watershed.Comparison of the two land cover maps (1972 and 2013) of the Bulgan sum river oasis showed a major change from natural rangeland to mostly built-up areas (+288%) and river water receiving sites (+594%). The Bulgan River watershed covers an area of 7409km2 and the river itself has a long-term annual average discharge of 9.53m3s−1. Overall, an area of 769ha was actively irrigated (2013). A total withdrawal of 555460m3 irrigation water was estimated, 86% of which was applied to hay fields (2013). The irrigation water productivity ranged from 5.38 (fruits of fruit trees) to 0.43 (hay) m3 kg−1 fresh matter yield and a related average income of 0.58 € per kg dry matter per m3. The SWAT model simulated an average evapotranspiration of 100mm and potential evapotranspiration of 993mm per year. Water-use efficiency varied from 11 to 52kg dry matter ha−1mm−1 for rangeland and wetland. Auto-irrigation (whenever plant growth drops below this threshold, the model will automatically apply water until field capacity is reached) and fertilization management simulated by the SWAT model increased yields of irrigated crops, vegetable, hay and fruit trees by about 46 and 77% on average. To enhance biomass productivity per unit water transpired and income per unit water applied, improved irrigation technologies and management practices would be needed.

Preliminary estimation of forage yield and feeding value of Lupinus angustifolius varieties cultivated in Jalisco, México, during the cool season

The effects of genotype and harvest date on lupin (Lupinus angustifolius) forage yield and quality were evaluated in Zapopan Jalisco, Mexico. Cultivars Haags Blaue, Boregine, Borlu, Probor, Sonate, and Boruta were grown during the 2013–2014 cool season and harvested twice, in January (early harvest) and February (late harvest). Fresh and dry matter (FM, DM) yield, crude protein(CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), minerals, and total alkaloids were measured at each harvest. FM yields varied from 9.1 to 12.2 t ha-1 and from 23.4 t ha-1 to 35.3 t ha-1 at the first and late harvests, respectively. DM yields from early harvest plants varied from 1.2 to 1.7 t ha-1; those from the second harvest (late harvest date) varied from 3.4 to 6.8 t ha-1. The highest CP content for both (early and late harvests) was identified in the Probor cultivar, at 226 and 187 g/kg, respectively. At early harvest, ADF values varied from 291.2 in Sonate to 392.3 g/kg in Borlu; at late harvest, ADF values varied from 417.2 in Sonate to 488.3 g/kg in Borlu. Harvest date and varieties did not influence alkaloid and mineral content.

Agronomic Evaluation of Sorghum Hybrids for Silage Production Cultivated in Semiarid Conditions.

The aim of this study was to study the agronomic traits of different Sorghum bicolor (L.) Moench hybrids for silage productionin semiarid conditions. It was a 1-year evaluation conducted in a randomized block design with 24 treatments and three replicates. The treatments were sorghum hybrids developed by the breeding program of “Embrapa Milho e Sorgo” (Brazilian Agricultural Research Corporation). The fresh matter yield (FMY) in the first cut varied from 22,643.56 to 44,033.15 kg/ha, with an average of 32,607.37 kg/ha, leading to the formation of two groups. Similar results were observed for the dry matter yield (DMY), in which the highest group yielded from 9,471.32 to 14,540.23 kg/ha dry matter (DM). For plant regrowth, there was an increase in the number of stems and a decrease in the amount of panicles. Two groups were formed for the accumulated dry matter yield (ADMY), averaging 14,217.91 kg/ha; the highest group showed mean values of 18,003.00 to 14,221.94 kg/ha. The evaluated sorghum hybrids exhibited satisfactory accumulated forage yields due to their high yield in regrowth, which indicates that they are suitable for use in animal production systems in semi-arid regions.

Methane yield performance of amaranth (Amaranthus hypochondriacus L.) and its suitability for legume intercropping in comparison to maize (Zea mays L.)

The use of amaranth as a new crop in biogas crop rotations has raised scientific interest Europe-wide over the past decade. However, the results of studies on its overall performance are somewhat contradictory. This study aims to investigate both the performance of amaranth (Amaranthus hypochondriacus L.) as a biogas crop in comparison to maize (Zea mays L.) and to test its suitability for intercropping with two different legume species. For this purpose, field trials were conducted in southwest Germany in 2014 and 2015. The two legumes common bean (Phaseolus vulgaris L.) and white clover (Trifolium repens L.) were chosen for intercropping with the main crops amaranth and maize. Each year, aboveground fresh matter yield, dry matter content (DMC), ash content and specific methane yield (SMY) were determined. The average methane yield per hectare (MYH) of all amaranth treatments was 3030.6±187.3m3N ha−1 in 2014 and 2265.6±243.4m3N ha−1 in 2015, approximately half that of maize each year. In 2015, the low MYHs stemmed from low dry matter yields (DMYs) caused by drought conditions. This effect was much stronger for maize than for amaranth. The average SMY over the two years was much lower for amaranth (266.0±1.7lNkg−1 of volatile solids (VS)) than for maize (330.0±1.5lNkg−1 of VS) due to higher contents of both ash (>13% of VS) and lignin (>6% of VS). Intercropping with common bean did not significantly affect the DMY and SMY of either main crop in either year. By contrast, the establishment of white clover was successful in both main crops and years. However, white clover also significantly decreased the DMY of both main crops in 2015. Overall, it was shown that amaranth and maize appear equally suitable for legume intercropping, but new amaranth genotypes and optimized cultivation techniques are required to render it a more productive biogas crop.

Plant Growth Pattern, Forage Yield, and Quality of Indigofera zollingeriana Influenced by Row Spacing

Indigofera zollingeriana is one of legumes has a great potential to be used as an animal feed having high quality nutrients and is tolerant to different environmental conditions. The objective of this experiment was to study the effect of different row spacings between individual plants on growth pattern, forage yield, and quality of I. zollingeriana. Field experiment was conducted at Field Laboratory of Agrostology, Faculty of Animal Science Bogor Agricultural University, during the growing season of 2015/2016. The 4 spacings levels used were 1 x 1.5 m; 1 x 1 m; 1 x 0.75 m; and 1 x 0.5 m. The treatment was arranged in a completely randomized block design, with 4 replicates. Variables in this research were plant height, number of leaves, number of branches, plant population for each plot, fresh and dry matter yields, and forage quality. The results showed that narrow plant spacing increased plant height, plant population, fresh and dry weights, dry matter yields, as well as NDF and β-carotene contents. The wider the plant spacing the greater the number of branches and leaves per plant. It was concluded that increasing plant population by narrowing plant spacing remained the most effective way to increase Indigofera forage yield without negative effects of it on nutritive values, i.e., crude protein, crude fat, crude fiber, ADF, and TDN.

Ground cover management and farmyard manure effects on soil nitrogen dynamics, productivity and economics of organically grown lettuce (Lactuca sativa L. subsp. secalina)

Ground cover management and farmyard manure (FYM) management have important roles in organic lettuce production. However, there is not enough information about their combined effects. In order to assess the effects of individual and combined ground cover and FYM management on soil mineral N (NH4-N and NO3-N) dynamics, lettuce yield and economics in organic farming, a two-year field experiment was conducted on a certified organic farm in Kisač (Vojvodina, Serbia). The experiment had a two-factorial split-plot completely randomized block design. FYM was applied on the half of the experimental field as a whole-plot factor, while ground cover management included the following four treatments: (I) control, without ground cover management (Ø); (II) hoeing (H); (III) agrotextile cover; (IV) straw mulch (SM), which were applied on split plots. The applied SM and AT increased soil moisture by 12.83 and 3.73%, respectively, compared to the control treatment. FYM increased soil mineral N concentration, the lettuce fresh matter (FM) yield and nitrate concentration in lettuce. However, nitrate concentration in lettuce in all treatments was below the limit required by the European Commission (EC) (2001). The highest lettuce yield was obtained by AT (39 122 kg), followed by SM (33 925 kg), and it was higher with FYM application by 16.85%. Hoeing did not positively affect the yield, probably due to its negative effect on soil moisture. Additional profit was higher with FYM, showing the following decreasing order: AT>H>SM>Ø. However, value/cost ratio (VCR) was in the order Ø>H>SM>AT on FYM fertilized plots. FYM application led to higher lettuce yield and higher profit and VCR. In case a farm does not have FYM, SM is the best alternative due to its positive effect on the yield and low investment costs.