Plant and seed nutrient uptake in common bean in seven organic and conventional production systems

Westermann, D. T., Terán, H., Muñoz-Perea, C. G. and Singh, S. P. 2011. Plant and seed nutrient uptake in common bean in seven organic and conventional production systems. Can. J. Plant Sci. 91: 1089–1099. Knowledge of plant and seed nutrient uptake by crop cultivars in organic and conventional production systems (PS) is essential for breeding the most appropriate genotypes for each PS. The objective was to determine the plant and seed uptake of nitrogen (N), phosphorus (P), potassium (K), copper (Cu), manganese (Mn), and zinc (Zn) by 16 common bean genotypes. We also identified genotypes efficient in plant and seed nutrient uptake across seven organic and conventional PS. A randomized complete block design with four replicates (one plot per replicate) was used for evaluation in each of seven organic and conventional PS in 2003 and 2004. The effects of plant and seed uptake of nutrients, genotypes, PS, and the genotype × PS interaction were significant (P≤0.05). Plant and seed uptake of nutrients decreased in on-station continual dry bean and drought-stressed and on-farm organic low-input compared with on-station conventional irrigated and on-farm organic high-input PS. Common bean genotypes with higher biomass yield, in general, also had higher nutrient uptake, regardless of PS. In general, N and P uptakes were high and that for Mn was markedly low among common bean genotypes. Pinto CO46348, Bill Z, and Othello and Mexican red NW-63 and UI 239 were high-yielding and used nutrients more efficiently across seven organic and conventional PS and years. Other cultivars either had low biomass and seed yield (e.g., Common Pinto, Topaz, Common Red Mexican, UI 59) or were more efficient at whole-plant uptake or seed uptake of nutrients, but not both (e.g., Matterhorn, UI 465). Use of the above five genotypes should be maximized for production in both organic and conventional PS, and for breeding high-yielding broadly adapted cultivars efficient in plant and seed nutrient uptake in organic and conventional PS.

The impacts of organic and conventional production systems on postharvest life and quality parameters of Batavia type 'Caipira' lettuce heads (Lactuca sativa L.) were investigated. Harvested lettuce heads grown in two different production systems were stored at 0 °C temperature and 95-98% relative humidity for 20 days in modified atmosphere packaging. The lowest weight loss, the highest ascorbic acid content and antioxidant activity were obtained from the organic production system (Org-2). The conventional production system had higher total soluble solids, titratable acidity, and total phenolic contents. During the shelf-life period at 20 °C, the weight losses of lettuce heads grown conventionally were higher than with the other production system. Conventionally grown heads had higher titratable acidity and total phenolic contents than organically grown heads. The highest titratable acidity and h° values were obtained from the plants grown under conventional and organic production systems (Org-2), while the highest chroma value and antioxidant activity were detected from the control treatment. The highest ascorbic acid content was detected in the control treatment, but the effects of control, organic (Org-2) and conventional production systems on ascorbic acid content were not statistically significant. The results indicated that the organic production system (Org-2) was the most effective treatment in prolonging postharvest life and protecting the quality of Batavia type 'Caipira' lettuce heads stored in modified atmosphere packaging. © 2018 Society of Chemical Industry.

Genotype by environment interaction for female fertility traits under conventional and organic production systems in Danish Holsteins

Given the environmental footprints of the conventional agriculture, it is imperative to test and validate alternative production systems, with lower environmental impacts to mitigate and adapt our production systems. In this study, we identified six production systems, four in Italy and two in Denmark, to assess the environmental footprint for comparison among the production systems and additionally with conventional production systems. SimaPro 8.4 software was used to carry out the life cycle impact assessment. Among other indicators, three significantly important indicators, namely global warming potential, acidification, and eutrophication, were used as the proxy for life cycle impact assessment. In Italy, the production systems compared were silvopastoral, organic, traditional, and conventional olive production systems, whereas in Denmark, combined food and energy production system was compared with the conventional wheat production system. Among the six production systems, conventional wheat production system in Denmark accounted for highest global warming potential, acidification, and eutrophication. In Italy, global warming potential was highest in traditional agroforestry and lowest in the silvopastoral system whereas acidification and eutrophication were lowest in the traditional production system with high acidification effects from the silvopastoral system. In Italy, machinery use contributed the highest greenhouse gas emissions in silvopastoral and organic production systems, while the large contribution to greenhouse gas emissions from fertilizer was recorded in the traditional and conventional production systems. In Denmark, the combined food and energy system had lower environmental impacts compared to the conventional wheat production system according to the three indicators. For both systems in Denmark, the main contribution to greenhouse gas emission was due to fertilizer and manure application. The study showed that integrated food and non-food systems are more environmentally friendly and less polluting compared to the conventional wheat production system in Denmark with use of chemical fertilizers and irrigation. The study can contribute to informed decision making by the land managers and policy makers for promotion of environmentally friendly food and non-food production practices, to meet the European Union targets of providing biomass-based materials and energy to contribute to the bio-based economy in Europe and beyond.

The objectives were to identify maize germplasm for the organic productions system and to compare the genetic effects of the grain yield of maize cultivars in organic and conventional production systems. Diallel crosses were made between six maize cultivars and the hybrid combinations were evaluated in conventional and organic production systems. The hybrid combinations produced different grain yields in the two production systems. The interaction between general combining ability and production systems was significant for grain yield, ear height and number of ears. This indicates that the additive genetic effects differ in organic and conventional production systems. The specific combining abilities (SCA) were significant for grain yield and plant height, indicating a significant difference between the non-additive effects. However, the SCA x production systems interactions were not significant for those traits. It was concluded that for the development of maize cultivars for the organic production system, selection must be made in the specific environment for the expression of favorable alleles that confer advantages for adapting to this system; the general combining ability of genitors is different for the two production systems, but the specific combining ability isn't different in organic and conventional systems.

For organic agriculture, wheat cultivars with good and stable grain yield across years are needed. Grain yield and hectolitre weight of 10 cultivars were estimated in field trials for three years at conventionally and organically production systems under the central part of Oltenia, Romania conditions. Our research evidentiated that cultivar influenced significant only hectolitre weight; production system influenced significant the both grain yield and hectolitre weight, and interaction between cultivars x production system was non-significant for the both traits. On average for the study period, the grain yield from the organic production system was by 35% lower than that achieved from the conventional production system. Hectolitre weight was also, affected by production system showing in the organic system values by 2% lower than in the conventional system. The cultivar Miranda was more stable than the other studied cultivars in both conventional and organic production system. On average most cultivars fulfilled the requirements for Grades 2 and 3, but the percentage of cases below the 72 kg/hl limit (non bakery value) varied from 0 to 66.7% in both production systems.

The effects of organic and conventional production systems on crop productivity have been greatly explored, but their effects on soil microbial processes were often neglected. A comparative field study of organic and conventional production systems was conducted at the Tennessee State University research farm to determine soil heterotrophic respiration and microbial biomass carbon. Leafy green vegetables were grown in a conventional production system in an open field, and they were grown in an organic production system, using three different row covers (agribon cloth, insect net, and plastic), and in an open field. Soil samples (0-15cm) were collected from the two production systems. Soil heterotrophic respiration rate (RH), microbial biomass carbon (MBC), and biomass-specific heterotrophic respiration rate (the inverse is used as a proxy for microbial carbon use efficiency) were quantified. The results showed that the conventional production system significantly increased RH relative to the organic system. Organic production system, however, significantly enhanced MBC and reduced biomass-specific respiration rate indicating an increase in carbon use efficiency. Although MBC remained unchanged among the row covers, insect net increased RH and biomass-specific heterotrophic respiration rate. Our results suggest that the organic production system not only promoted soil microbial abundance but also limited soil heterotrophic respiration to the atmosphere governed by the elevated carbon use efficiency.

This work aimed to evaluate the performance of potato genotypes in different regions in the organic and conventional production systems. The effect of plant stem development on tuber productivity was also investigated. Experiments were carried out (a) during the2020 spring season in Canoinhas-SC in the conventional production system, (b) in an organic cropping system during the 2021 winter season in Brasília-DF, and in both (c) conventional and (d) organic production systems during the 2022 winter season in Brasília-DF, Brazil. Eleven advanced clones as well as the control cultivars Atlantic (suitable for chips production), Markies and Asterix (suitable for French fries) were evaluated for tuber yield traits, specific gravity, and for the number and length of plant stems. The experimental design was randomized blocks with three replications. A higher productivity of marketable tubers was generally obtained by genotypes with longer stems, i.e. taller and more vigorous plants. A higher specific weight of tubers was obtained by genotypes with lower number of stems, which produced a lower number of tubers with higher average mass. Clones with good performance in both conventional and organic production systems were identified. The clones F18-13-03 and F65-13-06 showed high tuber productivity in both systems and a tuber specific gravity equivalent to the controls for French fries Asterix and Markies. The clones F36-13-08, ORG 2156 and F88-11-01 did not show the highest productivity in any of the environments. They showed a high number of tubers per stem and, consequently, the tubers had a reduced average mass. The clones F36-13-08 and ORG 2156 presented a high number of stems, suggesting the possibility of gains in marketable productivity under differentiated sprouting management of the seed tubers.

Potato is responsive to intensive agricultural input use; however, it can be produced in less intensive production systems (such as the organic system) by using appropriate production techniques and genotypes adapted to this system. This study aimed to evaluate the performance of advanced potato genotypes for tuber yield under conventional and organic production systems, in order to select potential genotypes to become new cultivars adapted to these systems. Fifteen advanced potato clones and two controls were evaluated under organic and conventional production systems, in 2016 and 2017, in Brasília-DF, Brazil. The experimental design was randomized blocks with three replicates and plots composed of two rows with 10 plants each, spaced 0.35 m between plants and 0.80 m between rows. Total (mass) and marketable (mass and number of tubers) productivities were evaluated. Variance analysis showed significant differences among genotypes for all traits. Despite the lower average tuber yield in the organic system, selecting genotypes with high potential productivity was possible in this system, such as F158-08-01 and F158-08-02, showing high marketable tuber yield, with values equivalent to the conventional system. Clones F102-08-04, F13-09-07, F-18-09-03, F-183-08-01, F-21-09-07, F31-08-05, F63-10-07 and F97-07-03 also outperformed the control cultivars in organic system. For conventional system, F158-08-01, F158-08-02 and F183-08-01 were superior, and F18-09-03, F21-09-07, F63-10-07, F97-07-03, PCDINV10 and PCDSE090 showed performance similar or superior to the most productive control (cultivar Asterix). Genotypes F158-08-01 and F158-08-02 were superior in both conventional and organic systems, with potential to become new cultivars recommended for both production systems.

Trials were conducted in 2011 and 2012 with ‘Aristotle’ bell pepper ( Capsicum annuum L.) grown under different tillage methods and irrigation regimes in organically and conventionally managed production systems. Treatments consisted of strip tillage or plastic mulch in well-watered or water-restricted irrigation regimes. Within organic and conventional production systems, the study was arranged as a split-plot randomized block design with strip tillage or plastic mulch as the main plot and irrigation regime as subplot. Leaf water potential (Ψ L ), soil penetration resistance (compaction), volumetric water content (VWC), soil temperature, and pepper yield were measured. Soil VWC was greater in strip-tillage plots compared with plastic mulch plots under both well-watered and water-restricted conditions for plots in the organic system in 2011 and conventional system in 2012. In addition, soil VWC was numerically lower, if not always statistically different, in water-restricted plots compared with well-watered plots. The trend of soil temperatures within each production system were similar in 2011 and 2012, with plastic mulch plots having slightly higher soil temperatures than strip tillage, despite using white-on-black plastic mulch. Midday Ψ L was affected by water regime, with well-watered plants having a significantly lower Ψ L than water-restricted plants; however, there were no effects of irrigation on predawn Ψ L . Tillage method and sampling location (between row and within row) significantly interacted to affect soil penetration resistance in 2011 and 2012. There was a significant interaction of tillage by irrigation regime on yield within conventional systems in both years, but not in organically managed plots. In 2011, yield data also indicated that the date at which 50% of marketable fruit were harvested (yield_mid) were later for strip–tillage-grown plants than plastic mulch–treated plants within conventional and organic production systems, respectively.

ABSTRACTHigh‐yielding cultivars adapted to stressed and nonstressed production systems (PS) would maximize efficiency of soil water and nutrient usage, compete well with weeds, resist diseases and insect pests, and reduce dependence on water, fertilizer, and pesticide. The objectives of this study were to (i) determine the performance of dry bean (Phaseolus vulgaris L.) landraces and cultivars across seven stressed and nonstressed PS, (ii) identify high‐yielding cultivars within and across PS, and (iii) determine associations among PS. Three landraces and 13 cultivars were evaluated for days to maturity, 100‐seed weight, and yield in 2003 and 2004. The PS and genotype effects and their interactions with years were significant (P < 0.01). The mean yield (740 kg ha−1), 100‐seed weight (28 g), and days to maturity (81 d) were least in the on‐farm organic low input (OFOL) PS. The greatest mean yield (2740 kg ha−1) was obtained in the on‐station conventional (OSCN) PS, while the greatest 100‐seed weight (35 g) and days to maturity (95) were obtained in the on‐farm low soil fertility (OFLF) PS. Red genotypes yielded more across all PS. ‘Bill Z’ in OSCN and on‐farm organic high‐input (OFOH) PS, ‘UI 239’ in on‐station continual bean production (OSCB), CO46348 in on‐station drought‐stressed production (OSDS), ‘Matterhorn’ in on‐farm conventional (OFCN), ‘NW 63’ in OFLF, and ‘Buster’ in OFOL had high yield. CO46348, UI 239, NW 63, and Bill Z had high yields across PS. Positive associations for yield in the OFCN occurred with yield across all PS except OFOL. The latter was not correlated with other PS. Thus, testing in the OFCN PS would be pivotal for development of high‐yielding cultivars for diverse PS, while testing at OFOL would need to be done for cultivars developed for use in that PS.

BackgroundThere has been a piqued interest in alternative agricultural production systems that are environmentally friendly due to concerns on how sustainable it is to grow conventionally. However, in the producer’s point of view, economic returns are an important issue in decision-making in adaptation. The purpose of this study is to assess the economic risk of conventional and organic sweetpotato production in the Southeastern US. The primary and secondary data were used for the analysis. We identified risk variables in stochastic profit function and performed Monte Carlo simulation in analyzing profitability and economic risk of conventional and organic production systems.ResultsFindings from the meta-analysis suggest lower sweetpotato yields and higher selling prices, are to be expected in the organic sweetpotato production systems compared with the conventional. A higher probability of having positive net return from organically grown sweetpotato compared to conventional production systems was observed.ConclusionsIncrease in unit cost leads to a decrease in net profit in both conventional and organic production systems. Sweetpotato price has more effect on net return compared to its yield in conventional production systems. The higher selling price, lower yield and lower unit costs provide a higher net profit return for the organic sweetpotato production systems. Unit cost in conventional production was noted to be higher in general, inferring conventional sweetpotato production could potentially experience a higher variability in net farm income. Despite the high production cost, however, farmers are encouraged to go into sweetpotato production as it appears to be profitable. Further studies should be conducted on conventional treatments without synthetic pesticides and fertilizers as these systems perhaps, may display lower external input costs that might make them more profitable similar to organic systems.

Conventional and organic semidwarf Granny Smith apple production systems were compared during three years of conversion to certified organic management. Because of differences in fruit load with hand thinning compared with chemical thinning, apple tonnage was higher in the organic production system (OPS) in 1989 and 1991. The organic system was higher than the conventional system in number and weight of fruit per tree, but smaller in average fruit size. Using grower-receivedfarmgate premiums of 38% (1990) and 33% (1991) for unsorted, certified organic apples, comparative cost accounting showed greater net return per hectare for the OPS. The OPS required higher material and labor inputs in all years.Greater terminal growth in the conventional production system (CPS) in 1991 was the only significant difference in growth indicators between systems. N was generally higher in leaf and new wood bark tissues in the CPS. P was generally higher in the leaf and new wood bark tissues in the OPS. No decline in yield was associated with increased weed biomass in the OPS. There was no difference in fruit damage caused by codling moth between production system treatments (codling moth granulosis virus and pheromone-based mating disruption vs. synthetic insecticide). In 1991, secondary lepidopterous pests (apple leafroller and orange tortrix) caused greater fruit scarring in the CPS. In all years, tentiform leafminers caused greater leaf damage in the CPS. Apple leafhopper density and leaf damage were greater in the OPS in 1990 and 1991.Soil nutrient levels showed few significant changes during conversion to organic management. Soil bulk density and water holding capacity were useful indicators of changes in soil physical characteristics. Potentially mineralizable nitrogen andmicrobial biomass-C were more sensitive indicators of system change than total N or organic C. Two soil biological ratios, the respiratory ratio and biomass-C/total organic-C, were similar in the two production systems. Earthworm biomass and abundance increased in the OPS in the third year. The introduction ofLumbricus terrestrisinto the OPS greatly increased litter incorporation rates.

Introduction Pulse crops with 18-32% protein are the most important source of grain for human food. Protein of food legumes due to the presence of essential amino acids such as Lysine, have high nutritional value. Common beans are half of the beans used in the world, its grains rich in protein and carbohydrates. Common bean is very sensitive to weather conditions and soil quality and its performance even in short periods of stress. About two-thirds of the land under cultivation in Iran is in semi-arid areas, so the varieties with resistance to drought stress are the most important objectives of the breeding programs. Genetic diversity is the base for the selection of genotypes with desirable traits. In addition genetic resources have the fundamental role for agricultural development, as a source of useful genes for resistance to biotic and abiotic stresses and the development of genetic adaptation to environmental changes considered that the proper utilization of these varieties can be produced new and more desirable plants. Materials & Methods In order to evaluate genotypic and phenotypic variation and determine the relationship between grain yield with other traits in 35 common bean genotypes under normal and drought stress conditions, an experimental design was carried out in a randomized complete block design under two conditions in 2013 at the research field of college of Agriculture and natural resource of University of Tehran in Karaj state with latitude 35° and 56 minutes north and longitude 50° and 58 minutes east and 1112.5 m height above sea level. Treatments consisted of 33 common bean genotypes with three Khomein, Daneshkadeh and Goli Cultivars as control, were selected from the collections of College of Agriculture, University of Tehran, Karaj. Based on 30 years of data, mean annual precipitation of 243 mm and the test run of 47.7 mm rainfall during the growing season was over. Planting was done manually. Each plot consisted of three rows of two meters in length and with a spacing of 50 cm and 10 cm seeds space on the row and depth of planting was about five centimeters. Irrigation took place similar to both conditions at flowering stage, for seven days (Equivalent to 70 mm evaporation) and after the vegetative growth and loss of the risk sufficient to remove the bushes. Irrigation of water stress piece was performed each 11 days (Equivalent to 110 mm evaporation). Harvest was performed when 90% of plants were matured and the seven plants in compliance with marginal effect of each plot were collected to measure traits and then by using the mean yield genotypes per plot in non-stress (Ypi) and stress conditions (Ysi), drought tolerance indices including, Mean Productivity, Geometric Mean Productivity, Harmonic Mean Productivity, Stress Tolerance Index, Stress Susceptibility Index, Tolerance Index, Yield Index, Yield Stability Index, Stress Intensity and yield reduction rate were calculated for each genotype. Results & Discussion Results showed that among genotypes in the studied traits there were significant differences which displayed genetic variation among the genotypes. Based on the average of genotypes yield in normal conditions the highest and lowest seed yield pertained genotypes 27 and 12, respectively, and in the stress related to genotypes 32 and 12, respectively. According to the results of phenotypic correlations, stepwise regression, and path analysis in both normal and stress conditions, the traits of seed and pod weight, biological yield, number of seeds per plant, and number of seed per pod were the most important and effective traits affecting yield. The highest diversity was observed for these traits; therefore the selection of these traits can ideally improve the yield. Based on factor analysis, five factors were selected that the total variation were explained 83.76 and 80.79 percent under normal and drought stress conditions, respectively. The first and second factors were named yield and yield component factors. Geometric Mean Productivity, Harmonic Mean and Stress Tolerance Index, indices had the highest significant correlation with yield in both conditions, hence, were introduced as the best indices for screening tolerant genotypes. Based on biplot graph, genotypes 25, 27 and 28 were identified as tolerant genotypes with high yield, whereas genotypes 7, 10, 22 and 23 as drought-sensitive genotypes. Based on indicators STI, GMP, GMP, HRM and performance in normal and stress conditions, using Ward method genotypes were classified in three clusters 21 genotypes in first class, 3 genotypes in cluster II and 11 genotypes were in Cluster III and tolerant genotypes with the highest distance from sensitive genotypes (cluster I) in the third cluster. Conclusion Thus, according to genetic distance can be genotypes in breeding programs to produce hybrids with high yield and drought tolerance can be used.

Soils present a limited resource for agricultural production and bear a vast diversity of organisms crucial for crop health and the provision of ecosystem services. There is growing evidence that agricultural practices affect soil microbial community structure and function but currently, there is a knowledge gap when it comes to tropical arable farming systems. In this study, we investigated the long-term impact of organic and conventional production systems on bacterial communities in two field trial located on a rhodic and humic nitisol in the Central Highlands of Kenya. The field sites operate on a full factorial design, testing farming systems (organic vs conventional) and input levels (high vs low). Including four field replication we assessed soil bacterial community structure via amplicon sequencing of the 16S rRNA gene and soils capacity for nitrification and nitrous oxide reduction via qPCR of functional genes (bacterial and archaeal amoA, nosZ) after 12 years of distinct management and before the start of the 5th three-year crop rotation period in 2019. The abundances of amoA bearing nitrifiers and nosZ bearing nitrous oxide reducers were enhanced in the high input organic production system on humic but not in rhodic nitisols. For both soil types, high input organic production system resulted in distinct bacterial community structure with enhanced bacterial richness compared to conventional and low input production systems. In rhodic and humic nitisols 160 and 84 OTUs were found to be indicative for organic production system at high input levels organic. Taxa associated with this system were identified as potential primary decomposers or symbionts related to plant nitrogen fixation, suggesting organic fertilization strategies such as manure composting as major driver for changes in soil bacterial community structure. This study reveals that organic production systems at high input levels on tropical nitisols translates to distinct soil bacterial communities with increased capacity for soil processes that are crucial for crop nutrient supply.