Cost efficiency of different cropping systems encompassing the energy crop Helianthus annuus L.

ArticleCrop rotation and green manure are the most ancient and popular cropping systems. This study sought to analyze the economic efficiency of sunflower where pea (Pisum sativum L.) either harvested or incorporated at the flowering stage in the soil before the sowing of sunflower in Europe and the final agricultural profit of such a cultivation system. Therefore, the main objectiveof this paper is to report the production costs and to find out which of the tested cultivation system gets sunflower cultivation economically viable in Greece and in Mediterranean region. To assess the economic efficiency, three-year field experiments were established in two contrasting environments in central Greece (Trikala and Larisa) and contained three different cultivation practices using legumes comprised the main-factor (T1: control, T2: legume incorporated at the flowering stage, T3: legume incorporated after seed harvest), while nitrogen fertilization comprised the sub-factor (N1:0, N2:50, N3:100 and N4:150 kgNha-1).The results derived from this study revealed the positive effect of the legume incorporation treatment (T2:legume incorporated at the flowering stage) where the final yield increased up to 5tha-1regardless region. Moreover, depending on the year the T2 treatment increases the final yield 30–50%and a yield increase was also noticed to the treatment where the legume was harvested (T3: legume incorporated after seed harvest). Therefore the introduction of this scheme into future land use systems in Greece and more generally in Mediterranean basin should be seriously taken into consideration

Ecology, Cultivation and Utilization of the Aromatic Greek Oregano (Origanum vulgare L.): A Review

Medicinal and aromatic plants represent a stable part of the natural biodiversity legacy of many countries in the world. The present review focuses on oregano (Origanum vulgare L.; family Lamiaceae), an endemic herb in Greece that constitutes one of the best known aromatic and medicinal plants originating in the Mediterranean region. In particular, oregano is an evergreen, rich in natural compounds perennial plant that received increased attention in the last years for a wide range of uses. Oregano dry leaves and inflorescences in mixture are used as human and animal food that is extremely rich in antioxidative properties. Additionally, its essential oil is rich in carvacrol, thymol, c-terpinene and p-cymene, and is used for a number of medicinal purposes, e.g. for inhibiting microbial and fungal toxin production as well as for the well-known anti-inflammatory, analgesic, antiarthritic, antiallergic, anticarcinogenic, antidiabetic, cardioprotective, gastroprotective, hepatoprotective, and neuroprotective properties. Due to its perfect quality and high essential oil concentration, Greek oregano (O. vulgare ssp. hirtum) is regarded among the best in the world gaining in popularity in the global markets for food industry applications. Consequently, oregano might be considered as an important low-input, environmental friendly commodity for extensive cultivation in Greece. The present review summarizes on the origin, the morphology, the ecology and the utilization of this plant. Despite the extensive literature available on the use of oregano biomass and essential oil, only few reports exist concerning the cultivation of this plant. Therefore, the present review is additionally focused on the cultivation practices and the importance of cultivation and utilization of Origanum vulgare L. in Greece and generally in the Mediterranean region in the near future, as it constitutes a plant species with high medical, economic and environmental value

Comparison of two perennial energy crops for biomass production at the end of their life cycle

Nowadays fossil fuels are decreasing, causing the world's interest in renewable energy sources to rapidly grow. One of the most interesting renewable and ecologically pure fuels is biomass, which is considered to be carbon neutral. Biomass is a promising source of energy, as it can be used directly as an energy resource. Its quality characteristics such as gross calorific value and ash content are of paramount importance so as to improve the combustion process. Furthermore, during the last three decades, there has been an increasing interest in the production of biomass pellets for domestic and industrial use. Alternative feed stocks will need to be sourced to meet the demand for biomass pellets. Investigation for new energy crops that produce high amounts of biomass under low inputs and of high energy efficiency are the main tasks of this field. Therefore, the aim of this study is to assess the biomass yield and the quality characteristics (gross calorific value and ash content) of two perennial energy crops (Cynara cardunculus L. and Panicum virgatum L.) growing in a typical soil (Fluventic Xerochrept) of the main agricultural land of central Greece. The comparison for both cultivated crops was made in order to show the results during their 8th growing year. The examined factors were the irrigation (two levels: irrigated and rainfed) and the nitrogen fertilization (two levels: 0 and 80 kg N ha-1 ) as well as their effect on the dry biomass yield and the gross calorific value. It was found that higher dry biomass yield was produced from cardoon (21.3 vs. 14.23 t ha-1 ), while the higher average gross calorific value was observed for switchgrass biomass (17.31 vs. 15.65 Mj kg-1 ). Finally, multiplying the dry biomass yield (t ha-1 ) with the gross calorific value (Mj kg-1 ) it was found that 334 and 245 Gj ha-1 from a cardoon and a switchgrass cultivation could be produced, respectively. Cardoon has better results than switchgrass probably due to the fact that switchgrass is growing from March till October; while cardoon’s growing period is from October to June and in such areas precipitation is in shortage during summer months. Both crops could achieve high amounts of energy per hectare and thus their introduction in future land use systems, for an environmentally friendly energy production should be seriously taken into consideration

Sorghum dry biomass yield for solid bio-fuel production affected by different N-fertilization rates

The objective of this study was to examine the effect on the dry biomass yield of two dfferent sorghum hybrids (H1 and H2) under five different N-fertilization levels (0, 70, 140, 210 and 280 kg ha-1 ) in a soil which was formed by lacustrine deposits of Karla Lake and is characterized from the downward movement of calcium carbonate from the surface horizons due to leaching (Fluventic Xerochrept) during 2017. The results demonstrated a significant effect (P < 0.05) of fertilization only for one hybrid. Biomass yield ranged from 22.2 to 37.5 t ha−1. For both hybrids, sorghum accumulated a high amount of biomass in stems. Dry stem/total biomass ratio was rather constant throughout the different fertilization treatments achieving 81.6 and 77.5% for the first (H1) and the second hybrid (H2), respectively. The second hybrid (H2) had a higher percentage of leaf biomass (20.1 vs. 13.8%) than the first (H1), but lagged behind in seed production (2.4 vs. 4.6%). Biomass dry matter partitioning and total dry weight are important selection criteria for energy crops, due to different gross calorific value and ash content but also because of the different economic importance they may have e.g. the seed is also used as animal feed. The above high biomass yields of sorghum, confirming the high potential of this crop, should be taken into serious consideration regarding land use planning, but further investigation for the gross calorific value and the ash content is needed as well as biomass characteristics that are quite important in case to improve the combustion process

Switchgrass (Panicum virgatum L.) nutrients use efficiency and uptake characteristics, and biomass yield for solid biofuel production under Mediterranean conditions

Switchgrass produces high amounts of biomass that can be used for solid biofuel production. In this study, the dry biomass yield vs. N-P-K nutrient uptake relations as well as the N-mineralization and the N-fertilization recovery fraction for switchgrass (cv. Alamo) were determined under field conditions for three N-fertilization (0, 80 and 160 kg ha(-1)) and for two irrigation (0 and 250 mm) levels, in two soils in central Greece with rather different moisture status over the period 2009-2012. It was found that dry biomass yield on the aquic soil may reach 27-30 t ha(-1) using supplemental irrigation, and remain at high levels (19-24 t ha(-1)) without irrigation. In the xeric soil, however, lower biomass yields of 14 -15 t ha(-1) may be produced with supplemental irrigation. The average N-concentration varies between 0.23% in stems and 1.10% in leaves, showing the very low needs in N. P-content varies between 0.16% in leaves and 0.03% in stems, whereas K-content fluctuates between 0.67% and 0.78%. Linear biomass yield-nutrient uptake relationships were found with high R-2, pointing to nutrient use efficiencies of 240 and 160 kg kg(-1), for N and K respectively. The base N-uptake ranged 70-84 kg ha(-1) in the aquic to 60 kg ha(-1) or less in the xeric soil. N-recovery fraction was about 30% in the aquic soil and lower in the xeric. Therefore, switchgrass is very promising for biomass production and its introduction in land use systems (especially in aquic soils of similar environments) should be seriously taken into consideration. (C) 2014 Elsevier Ltd. All rights reserved

Assessing interrill erosion rate from soil aggregate instability index, rainfall intensity and slope angle on cultivated soils in central Greece

In order to develop anew formula for assessing interrill erosion rate by incorporating the soil aggregate instability index, beta, erosion plots at seven sites in central Greece were used to measure interrill erosion rate under natural rainfall conditions during, a 39-month period. Soils classified as Alfisols, Inceptisols and Entisols with slopes 7-21%. moderately well to excessively drained, clay to loamy textured. were Studied. Runoff and total sediment were collected after each ponding rainfall event. The equation E-i = 0.628 beta S-t(1.3) e(0.6967/30) was finally proposed (R-2 = 0.939. P < 0.001) to describe interrill erosion rate. The term, S-t represents the tangent of the slope angle, and 130 represents the maximum rainfall intensity in 30 min. The addition of the aggregate instability index to improve existing methodologies provide was considered to provide an easy to determine and reliable measure of soil erodibility. Validation with independent data showed that the model predicted interrill erosion well (R-2 = 0.766. P < 0.001). Therefore, the proposed model based on the aggregate instability index, beta, has the potential to improved methodology for assessing interrill erosion rate. (C) 2004 Elsevier B.V. All rights reserved

Innovative Nitrogen Fertilizers Effect on Cotton Cultivation

Fertilizer enhancement is determined by chemical and physical characteristics, environmental safety, and mechanical stress stabilization, etc. In order to assess the reaction of cotton cultivation to distinct kinds of fertilizer (Agrotain: fertilizers with urease inhibitor versus standard urea) and different nitrogen dressings on chlorophyll content and yield, field studies were performed at two distinct locations (Palamas and Velestino) for 2 years (2014 and 2015). Cotton variety Flora was cultivated using Agrotain (with urease inhibitor) versus standard (urea) fertilizers under various N-dressings (0, 70, 140, and 210 kg ha−1). It was found that plants fertilized with Agrotain obtained higher chlorophyll content and achieved considerably higher yield during the second experimentation year owing to the efficient release and uptake of nitrogen from the plants. The variations between the examined fertilizers may be due to smoother, more stable N-nutrition and greater rates of photosynthesis. Nitrogen Use Efficiency was the same independently fertilization type, reinforcing the hypothesis that Agrotain fertilizers can lead to less N-losses, which is confirmed from the higher Agrotain recovery fraction. Therefore, the application of urease inhibitor fertilizers may decrease N-application and N-losses and it is advisable to introduce them to nutrition situations. © 2020, © 2020 Taylor & Francis Group, LLC

Relations between crop rotation with pea and soil structure

Agricultural practices such as crop rotation affect soil physical, chemical and biological properties. Legumes crop effect has been shown to provide several agro-ecological services as previous crop. The aim of the present fi eld study was to examine the effect of legumes in a crop rotation scenario to the soil structure by incorporating green biomass at the fl owering stage of pea. Two fi eld experiments were established in two different soils (sandy and clayey) for three years, where four different nitrogen dressings and three different cultivation practices using pea in rotation were used. Soil samples were collected at two depths (0-20 and 20-40 cm), fi ve times during the experimentation from the establishment till the end. An easier and rapidly soil classifi cation according to the agglomerate stability was used through the coeffi cient of instability β. It was found that in the sandy soil both green and pea rotation had a signifi cant effect on the improvement of the soil structure resulting from the decrease in the β instability index. Improving the soil structure will also lead to higher yields to the following crop. © 2019, Agricultural Academy, Bulgaria. All rights reserved

Assessing the efficiency of different fertilizer type and levels on maize yield

Many commercial compounds exist that promise the increasing efficiency of urea fertilizers by inhibiting urease activity in soils. Such a compound gaining in commercial importance in the last decades is N-(n-butyl) thiophosphorictriamide, broadly known with its registered trade name of “Agrotain”. In this study, the effect of nitrogen fertilizer dressings using Agrotain versus conventional (urea) fertilizers was studied under field conditions. In particular, the effect of three different nitrogen dressings using conventional N-fertilizers and Agrotain was investigated on the growth and final yield of maize cultivation at 2 different sites (Palamas and Velestino) and two years (2014 and 2015) in central Greece. Urease inhibitor ensures crops N-nutrition for longer period compared to conventional fertilizers. This results in better utilization of supplied nitrogen, achieving ultimately higher yields. It was demonstrated that crop fertilized with Agrotain obtained greater chlorophyll contents and reached significantly higher biomass and grain yields comparing to the treatments receiving traditional nitrogen fertilization, due to the more effective nitrogen release and uptake by the crops. The differences between the examined fertilizers are possibly due to smoother and stable N-nutrition and the higher photosynthesis rates. Therefore, application of urease inhibitor fertilizers, such as Agrotain, might reduce nitrogen application dressings, reduce N-losses and nitrification, and their introduction to existing crop rotations is highly advisable. © 2020, Agricultural Academy, Bulgaria. All rights reserved