Organic Crop Management Research Articles

Evaluation of an Organic Package of Practice Towards Green Gram Cultivation and Assessment of its Effectiveness in Terms of Crop Sustainability and Soil Quality Development

Restoration of soil has been identified as the option; to ensure crop sustainability. However, as per Trophobiosis Theory of French Scientist F. Chaboussou, focus on development of healthy plants is necessary to abate pest and disease invasion so as to ensure sustained crop performance, even under unfavorable environmental conditions. The present study, in randomized block design with green gram as test crop; was undertaken in Krishi Vigyan Kendra (Howrah, West Bengal) to evaluate the effectiveness of Inhana Rational Farming (IRF) Technology towards crop yield and soil quality development under different sustainable models viz. organic cultivation, integrated soil with organic crop management and non- chemical crop management; as compared to conventional farming practice. Highest yield was recorded under organic (933 kg ha-1) followed by integrated (921 kg ha-1) and non- chemical plant management (902 kg ha-1). The results were well corroborated with the plant development index obtained under these treatments. Favorable trend of soil quality under sustainable models especially in terms of microbial properties indicated the role of quality compost towards speedy rejuvenation of soil dynamics. The study indicated that reduction of synthetic fertilizers and qualitative management of soil is essential to restrict yield decline. However, plant management shall be prerequisite for ensuring crop sustainability without any time lag and under the changing climatic patterns. In this respect the potential of IRF Technology has been well accounted.

Effects of organic and conventional crop management on vineyard biodiversity

Abstract Although organic farming is rapidly expanding in the vineyards of southern Europe, conventional crop management, using treatments that require a number of chemical inputs to guarantee yields is still the most common approach to crop management. To gauge the effects of these management systems on biodiversity, communities of vascular plants, butterflies, moths and birds were studied in vineyards in the Priorat Appellation of Origin (Catalonia, NE Spain). Measurements inside plots (all four taxonomic groups) and in grass strips between crop lines (only butterflies and vascular plants) were taken in organically and non-organically treated vineyards. Crop treatment was found to have an important effect, stronger on the most sessile organisms. Organic farms hosted consistently richer communities of both vascular plants and butterflies, a trend that was also observed − albeit less significantly − in moths. The weaker response in this group was probably due to insufficient sampling. Birds, the most vagile of the surveyed taxa, showed no significant response to treatments. Grass strips acted in all cases as reservoirs of biodiversity and hosted richer assemblages. The current trend of placing vineyards on slopes without terracing should ensure the existence of uncultivated strips within the vineyards to enhance the biodiversity of these agroecosystems. As well, parameters such as altitude and urban surface area are important drivers of biodiversity in this region. Our results suggest that organic farming may contribute to halting the widespread decrease that is occurring in communities of butterflies and other insects in this region.

Adapting spring wheat breeding to the needs of the organic sector

Organic farmers and food processors need plant varieties that are adapted to their crop husbandry and processing practices. Such varieties are scarce as the mainstream breeding sector focuses on developing varieties for the conventional product chain that has different goals and practices. In this paper we study the case of the Dutch bread production chain to assess options that might enhance the availability of varieties suitable for the organic sector. The research involves an analysis of organic crop management and food processing practices and associated variety requirements. The research shows that several variety traits prioritized by the organic sector are not adequately addressed by conventional plant breeders: high baking quality, weed suppressiveness and tolerance to harrowing. Some of the interviewed conventional breeders are willing to consider technical adjustments to their breeding programmes. However, seed legislation and company economics limit the space to implement such modifications. We conclude that developing spring wheat varieties for the organic bread production chain requires breeders to prioritize selection for high baking quality genotypes that tolerate an organic weed management regime. This would require a concerted initiative of all actors in the organic bread production chain that includes establishing new socio-economic partnerships to overcome current economic and legal barriers.

From selection to cultivation with the support of all stakeholders: the first registration in France of two winter bread wheat varieties after value for cultivation and use evaluation in organic farming systems

Winter bread wheat is the most important cash crop for French organic farmers. The choice of its varieties farmers cultivate is therefore very important. Most of the available varieties were initially bred for intensive “conventional” farming systems (with high inputs of mineral fertilizers and pesticides). Thus, screening current and novel varieties for organic conditions is necessary to identify varieties suitable for organic farming conditions in a short-term experiment. After 18 years of breeding and screening in a combination of both low input and organic crop management systems, the two pure lines Hendrix and Skerzzo were registered in the official French catalogue with the special mention “organic farming.” The acreages of commercial seed production to be sold to organic farmers continuously increased from 120, 139 to 160 ha in 2013, 2014, and 2015, respectively. This successful process was made possible due to the support of the whole agricultural organic economic sector associated with the initiative.

Yield and apparent dry matter and nitrogen balances for muskmelon in a long-term comparison between an organic and a conventional low input cropping system

Nine-year yields and apparent balances of dry matter and nitrogen (N) are reported for muskmelon cultivated in a long-term comparison trial between an organic and a conventional low input system in Central Italy. In every year, yield, above ground biomass and N accumulation of each cash crop, green manure and weeds, and the partitioning between marketable yield and crop residues were determined. Apparent dry matter and nitrogen balances were calculated at the end of each crop cycle by taking into account the amounts of dry matter and ex novo N supplied to the system as green manure legume Ndfa (i.e., an estimate of N derived from the atmosphere via symbiotic fixation) and fertilisers, and those removed with marketable yield. Differences between systems varied across years. On average, organic muskmelon yielded 16% less than the conventional one, while the fruit quality was similar in the two cropping systems. Fruit ripening began one week later and it was more scaled than in the crop grown conventionally. This was the consequence of a slow initial growth of the organic crop, due to inadequate green manure N total supply or timing of N release. Moreover such a wide spaced crop (0.5 plants m–2, in rows 2 m apart) was not efficient in intercepting N released from green manure biomass incorporated broadcast. Compared to the conventional crop management, the organic crop management resulted in much higher organic matter supply to the soil and in higher residual N after harvest. Thus, the choice of cultivating wheat just after melon to prevent postharvest residual N loss appears a key strategy especially in organic systems. Fall-winter green manure crops contributed to the self-sufficiency of the organic system by supplying muskmelon with either N absorbed from the soil or ex novo legume Ndfa.

Labile factions of soil organic matter and microbial characteristics of soil under organic and conventional crop management systems

The aim of this study was to compare contents of labile fraction of soil organic matter and microbial parameters in soil under winter wheat and spring wheat grown according to organic, without animal manure application, and conventional crop management systems. Particulate organic matter fraction in the organically managed soil was significantly higher by 26% than that in the soil under the conventional farming system. Culturable colony forming units of bacteria and fungi, dehydrogenase and alkaline phosphatase activities, as well as C contents in microbial biomass and in hot water extracts (HWE) were significantly higher for the organic soil than for the conventional system. HWE prepared from both soils contained almost the same amounts of total N, but microbial biomass-N was higher in the organic soil. These results indicate that organically managed soils can maintain a high biological activity and substantial pools of readily available nitrogen even without application of animal manures.

Integrated Management of Crop Health in Response to Climate Variation in Commercial Open Field Tomato Production: Lessons Learned from the South African Experience (2003-2010)

South African open field tomato production occurs primarily in the Limpopo province and contributes significantly to the socio-economic stability of thousands of employees, suppliers and their dependents. Since 2003, these South African tomato producers practiced intensive open field tomato production using a combination of synthetic and organic crop management technologies. The objective of this study was to analyze these production practices and its effect on yield and marketability in terms of prevailing climate conditions. We studied these interactions for three different planting times within the year over an eight-year period by means of multivariate statistical techniques, including Classification and Regression Tree (CART) analysis. The results showed that complex interactions between biotic and abiotic variables influenced tomato yield and quality in each planting window. No crop or soil management option could defer the negative impact of climate variation on yield within unsuitable planting windows. The complex interaction between ecology and economics was confirmed. The ecosystem impact quotient (EIQ) of pesticide usage was significantly higher (P<0.001) in the unsuitable planting window due to disease-conducive climate conditions and the producer's response to subsequent problems. However, market prices were usually higher for produce planted in the unsuitable planting window. Increasing production costs has since forced these producers to abandon the unsuitable planting time and explore geographical alternatives in order to maintain profitable year-round tomato supply. In response to disease-conducive climate conditions, the sustained but sensible use of synthetic pesticides ensured high yield in the suitable planting windows. Although on-farm produced organic crop protectants were applied, efficacy was inconsistent. Planting time optimization was the best systems-level intervention for mitigating the risks of climate variation. At the practical level, sustainable open field tomato production depended on the integration of synthetic crop nutrition, synthetic and organic crop protection, disease-resistant cultivars, and cultivation in healthy soils.

Impact of organic crop management on suppression of bacterial seedling diseases in rice

Organic farming systems can effectively control the pathogens that cause plant diseases. When rice seedlings inoculated with Burkholderia glumae at germination were cultivated on each of three independent organic soils supplied by organic growers, or on conventional soil as a control, development of seedling rot symptoms was significantly suppressed on all organic soils, but not on conventional soil. This disease-suppressive activity of the organic soils was also observed for rice seedling damping-off disease caused by Burkholderia plantarii. Interestingly, such disease suppression was completely compromised on organic soils sterilized at 121 °C, indicating biological activity included in organic soils seems to be associated with the suppression of rice seedling diseases. To explore the putative biological factor(s) conferring the disease-suppressive activity of organic soils, we isolated bacteria from the filtrates of organic soil suspensions. Among these filtrates, two bacterial isolates could suppress development of bacterial seedling rot symptoms, whereas Escherichia coli as a control could not. The 16S rDNA and rpoD nucleotide fragment sequences of two bacterial isolates conferring the observed disease-suppressive activity were highly homologous to those of Pseudomonas sp. Furthermore, phylogenetic analysis of these nucleotide sequences suggested that two isolates placed in the P. fluorescens group. These results reveal that certain Pseudomonas sp. that inhabit organic soils likely play a role in the suppression of rice seedling diseases in organic farming systems.

Endophytic fungal diversity in coffee leaves (Coffea arabica) cultivated using organic and conventional crop management systems

Endophytic fungi dwell in the tissues of plants without causing disease symptoms. Coffee production can be performed using conventional or organic crop systems. Studies have been carried out to assess the endophytic fungal community in a conventional coffee crop system. However, little is known about them in organic conditions. Comparisons were made between an endophytic fungal community from leaves of Coffea arabica in organic and conventional crop systems. Mature and healthy leaves of C. arabica were collected from two crop systems during the wet and dry seasons, in the Northeast Brazil. A total of 432 fragments were analyzed and 336 specimens of endophytic fungi were isolated and distributed among 16 genera and 17 species. Colletotrichum gloeosporioides complex and Phyllosticta capitalensis were the most common fungi in conventional and organic crop systems, respectively. The largest number of fungal endophytes was observed during the wet season, although the diversity index and species richness were higher in the dry season. The endophytic fungal communities in conventional and organic crop systems exhibited 50.61% similarity, with six species occurring uniquely in organic and five in conventional coffee. Therefore, more research is needed to confirm that the species could be used as indicators of these management systems.

Comparison o Selection Results i Organic and Conventional Environments for Winter Triticale

×One of key questions in breeding for organic agriculture is about most appropriate selection environment. A successful man-made cereal species, triticale (Triticosecale Wittm. ex A. Camus.) - is very suitable for growing in organic crop management systems but little research has been conducted on breeding triticale for organic agriculture. Field trials were carried out in Priekuïi during 2009-2012. One hundred F4 winter triticale lines were sown in conventionally and organically managed fields. Selection of the approximately ten best lines in each environment, according to breeders’ opinion with respect to suitability for organic conditions, was made. The selected lines were compared in both organic and conventional fields. The study did not show that there was a need to create varieties for organic farming by selection of triticale in the initial generations in organic fields.

The influence of organic and conventional fertilisation and crop protection practices, preceding crop, harvest year and weather conditions on yield and quality of potato (Solanum tuberosum) in a long-term management trial

The effects of organic versus conventional crop management practices (fertilisation, crop protection) and preceding crop on potato tuber yield (total, marketable, tuber size grade distribution) and quality (proportion of diseased, green and damaged tubers, tuber macro-nutrient concentrations) parameters were investigated over six years (2004–2009) as part of a long-term factorial field trial in North East England. Inter-year variability (the effects of weather and preceding crop) was observed to have a profound effect on yields and quality parameters, and this variability was greater in organic fertility systems. Total and marketable yields were significantly reduced by the use of both organic crop protection and fertility management. However, the yield gap between organic and conventional fertilisation regimes was greater and more variable than that between crop protection practices. This appears to be attributable mainly to lower and less predictable nitrogen supply in organically fertilised crops. Increased incidence of late blight in organic crop protection systems only occurred when conventional fertilisation was applied. In organically fertilised crops yield was significantly higher following grass/red clover leys than winter wheat, but there was no pre-crop effect in conventionally fertilised crops. The results highlight that nitrogen supply from organic fertilisers rather than inefficient pest and disease control may be the major limiting factor for yields in organic potato production systems.

Variation of nitrogenous components in potato (Solanum tuberosum L.) tubers produced under organic and conventional crop management

The information related to protein and other nitrogenous components in organically produced potato tubers can be interesting for consumers with specific diets. Such information is still limited. Here we report results on the effects of organic and conventional production systems on accumulation of nitrogenous substances including total tuber protein and the nutritiously most important tuber protein, patatin, observed in five cultivars on two localities during three consecutive years. Organically produced potato tubers contained significantly lower content of total nitrogen, crude protein, nitrates and glycoalkaloids (α-solanine and α-chaconine). Protein content, patatin relative abundance in total tuber protein and patatin content in organically produced potato tubers were slightly lower than in conventional ones but the differences were not statistically significant. The cultivar and interactions between cultivars and other production factors affected considerably contents of crude protein, protein, glycoalkaloids and patatin relative abundance. The effect of cultivar on these nitrogenous characteristics was stronger for potatoes produced under conventional farming indicating the sensitive reaction of organically produced potatoes on less favourable agro-ecological production conditions. The results indicate that cultivar-specific genetic factors play the predominant role in the reciprocal interaction with other cultivation factors affecting the nitrogenous qualitative parameters of organically produced potato tubers. This should be considered to include primarily the cultivar in quality standards of organic farming. The late maturing cultivar Bionta exhibited high instability in tubers yield, total protein and patatin protein characteristics when produced under organic farming system, while the early maturing cultivar Karin reacted on the conditions of organic farming by an increase of the patatin content.

Soil chemical properties under organic and conventional crop management systems in south Poland

There is a great need to assess the impact of farming methods on soil fertility, especially in specific ecoregions. In Poland, relatively limited research has been conducted on soil quality and fertility in organic, dynamically developing agricultural systems. A comparative study on soil parameters under organic and conventional cultivation was performed in 2009. Twenty-two pairs (organic-conventional) of fields located in the south and east of Poland were chosen. All organic sites were certified. The following field crops were investigated: apple, pear, blackcurrant, carrot, beetroot, and celery. The soil granulometric composition, total organic content, total nitrogen, as well as the content of available macroelements (P, K, Ca, Mg, S), microelements (Cu, Fe, Zn, Mn, B), and trace elements (Cd and Pb) were measured. The organic farm soils had a higher level of the total organic matter (2.02%) than the conventional (1.75%). The organic system increased the total soil N level in celery and beetroot fields. Low or very low concentrations of available P in organically managed orchards were observed in individual farms, whereas excessive soil P amounts were noted for organic beetroot and celery fields. Differences in soil K concentration caused by the farming system were found only for red beet. Ca concentration was higher in the conventional than in the organic soil only for celery. There was a higher soil available Cu concentration for all of the investigated conventional vegetable fields than for the organic. The reverse was true for the apple and blackcurrant farms. The highest levels of Cd and Pb were noted in soils sampled from some organic celery fields.

Impacts of Organic and Conventional Crop Management on Diversity and Activity of Free-Living Nitrogen Fixing Bacteria and Total Bacteria Are Subsidiary to Temporal Effects

A three year field study (2007–2009) of the diversity and numbers of the total and metabolically active free-living diazotophic bacteria and total bacterial communities in organic and conventionally managed agricultural soil was conducted using the Nafferton Factorial Systems Comparison (NFSC) study, in northeast England. Fertility management appeared to have little impact on both diazotrophic and total bacterial communities. However, copy numbers of the nifH gene did appear to be negatively impacted by conventional crop protection measures across all years suggesting diazotrophs may be particularly sensitive to pesticides. Impacts of crop management were greatly overshadowed by the influence of temporal effects with diazotrophic communities changing on a year by year basis and from season to season. Quantitative analyses using qPCR of each community indicated that metabolically active diazotrophs were highest in year 1 but the population significantly declined in year 2 before recovering somewhat in the final year. The total bacterial population in contrast increased significantly each year. It appeared that the dominant drivers of qualitative and quantitative changes in both communities were annual and seasonal effects. Moreover, regression analyses showed activity of both communities was significantly affected by soil temperature and climatic conditions.

Effect of Buckwheat and Potato as Forecrops on Soil Microbial Properties in Crop Rotation

Field trials were carried out at the experimental cereal breeding fields in Stende (Latvia), an area characterized by a northern temperate climate. The soil had been under short-term organic or conventional crop management and was then subjected to crop rotation, using buckwheat (Fagopyrum esculentum Moench.) and potato (Solanum tuberosum L.) as the forecrops; wheat (Triticum aestivum L.) and oat (Avena sativa L.) as the following crops; and two fertilizer regimes under common organic and conventional practices. As the evaluation criteria of the soil quality, physico-chemical (pH value, organic matter, N, P, K) were tested. In addition, the following biological properties were estimated: plate counts of different physiological groups of microorganisms, soil microbial respiration, enzymatic activity (urease, dehydrogenase and fluoresceine diacetate hydrolysis) of soil microorganisms. Soil microbial respiration activity, FDA hydrolysis and urease activity showed a tendency to decrease in the soil after potato cultivation as the forecrop. The number of bacteria was higher in plots with wheat, and the actinomycete count was lower after oat cultivation. The number of bacteria, actinomycetes, fungi, as well as soil microbial respiration and enzymatic activity, fluctuated due to weather seasonality.

A long‐term comparison of the influence of organic and conventional crop management practices on the content of the glycoalkaloid α‐tomatine in tomatoes

α-Tomatine, synthesized by Lycopersicon and some Solanum species, is a steroidal glycoalkaloid which functions to protect against pathogens and insects. Although glycoalkaloids are generally considered toxic, α-tomatine appears to be well tolerated in humans. α-Tomatine has numerous potential health benefits including the ability to inhibit cancer cell growth in in vitro studies. α-Tomatine is influenced by numerous agronomic factors including fertilization and nitrogen availability. Herein, the levels of α-tomatine were compared in dried tomato samples (Lycopersicon esculentum L. cv. Halley 3155) produced in organic and conventional cropping systems that had been archived over the period from 1994 to 2004 from the Long Term Research on Agricultural Systems project (LTRAS) at UC Davis. The α-tomatine levels of tomatoes in both cropping systems ranged from 4.29 to 111.85 µg g(-1) dry weight. Mean levels of α-tomatine were significantly higher in the organically grown tomatoes than conventional ones (P < 0.001). In the organic management system, α-tomatine content was also significantly (P < 0.001) different between cropping years, suggesting that other influencing factors such as environmental conditions also affect α-tomatine content in tomato. The organically produced tomatoes had higher average α-tomatine content than their conventional counterpart over the 10-year study. Significant annual variability in the α-tomatine content in tomatoes was also observed and suggests that environmental factors, external to nitrogen fertilization, influence α-tomatine content in tomatoes.

Organic Crop Management Enhances Chicoric Acid Content in Lettuce

L- chicoric acid is a dominant phenolic compound in lettuce (Lactuca sativa L.) and has been shown to accumulate in response to many abiotic stresses and crop management practices. It is a potent inhibitor of human immunodeficiency virus (HIV-1) integrase needed for the replication of this virus and for the productive infection of the host cell. L- chicoric acid has been found to act synergistically in combination with anti-HIV drugs used for treating acquired immuno-deficiency disorder (AIDS). We show in this study that organic management practices increase the chicoric acid content by nearly 2-fold compared to conventional management practices while they did not have a significant effect on the overall accumulation of phenolic compounds and antioxidants. Similar increase was observed in quercetin-3-O-glucoside under organic management. In addition, pre-plant fertilization decreased the levels of many phenolic compounds including chicoric acid under organic management unlike under conventional management. However, organically managed crop without pre-plant fertilization had better growth and produced about 2.5 times higher yield and higher chicoric acid content than did the conventionally managed crop. Thus, the results show that long term organic crop management practices, but avoiding pre-plant fertilization, can significantly enhance the yield of antiretroviral agent chicoric acid in lettuce.

Effect of Organic and Conventional Crop Rotation, Fertilization, and Crop Protection Practices on Metal Contents in Wheat (Triticum aestivum)

The effects of organic versus conventional crop management practices (crop rotation, crop protection, and fertility management strategies) on wheat yields and grain metal (Al, Cd, Cu, Ni, Pb, and Zn) concentrations were investigated in a long-term field trial. The interactions between crop management practices and the season that the crop was grown were investigated using univariate and redundancy analysis approaches. Grain yields were highest where conventional fertility management and crop protection practices were used, but growing wheat after a previous crop of grass/clover was shown to partially compensate for yield reductions due to the use of organic fertility management. All metals except for Pb were significantly affected by crop management practices and the year that the wheat was grown. Grain Cd and Cu levels were higher on average when conventional fertility management practices were used. Al and Cu were higher on average when conventional crop protection practices were used. The results demonstrate that there is potential to manage metal concentrations in the diet by adopting specific crop management practices shown to affect crop uptake of metals.

The influence of organic and conventional crop management, variety and year on the yield and flavonoid level in common buckwheat groats

Common buckwheat (Fagopyrum esculentum Moench) is a pseudocereal that is cultivated for its achenes that possess a high level of flavonoids. Some scientific studies have found that the growing conditions can significantly affect the flavonoid content in conventional and organic food products. Hence, the present study compared conventionally and organically produced common buckwheat with respect to the content of selected flavonoids, thousand achenes weight and achene yield. Three buckwheat varieties were grown with organic and conventional crop management under the same environmental conditions. The thousand achenes weight and achene yield were not significantly influenced by way of crop management. The level of rutin, epicatechin, catechin, and epicatechin gallate in buckwheat groats (hulled achenes) were quantified with high pressure liquid chromatography. Only rutin and epicatechin gallate reached significantly higher level in organic groats. However, the differences were influenced by environmental conditions in the given year and variety.

Agroecosystem Management and Nutritional Quality of Plant Foods: The Case of Organic Fruits and Vegetables

Organic and conventional crop management systems differ in terms of the fertilisers and plant protection methods used. Ecological and agronomic research on the effect of fertilization on plant composition shows that increasing availability of plant available nitrogen reduces the accumulation of defense-related secondary metabolites and vitamin C, while the contents of secondary metabolites such as carotenes that are not involved in defense against diseases and pests may increase. In relation to human health, increased intake of fruits and vegetables is linked to reduced risk of cancer and cardiovascular disease. This benefit may be primarily due to their content of defense-related secondary metabolites, since most other constituents of fruits and vegetables either are not unique to these foods or have been shown to not provide health benefits when the intake is increased. A meta-analysis of the published comparisons of the content of secondary metabolites and vitamins in organically and conventionally produced fruits and vegetables showed that in organic produce the content of secondary metabolites is 12% higher than in corresponding conventional samples ( P< 0.0001). This overall difference spans a large variation among sub-groups of secondary metabolites, from a 16% higher content for defence-related compounds ( P< 0.0001) to a nonsignificant 2% lower content for carotenoids, while vitamin C showed a 6% higher content ( P= 0.006). Based on the assumption that increasing the content of biologically active compounds in fruits and vegetables by 12% would be equivalent to increasing the intake of fruits and vegetables by the same 12%, a model developed to calculate the health outcome of increasing the intake of fruits and vegetables was then used to tentatively estimate the potential increase in life expectancy that would be achieved by switching from conventional to organic produce without changing the amount consumed per day, to 17 days for women and 25 days for men.