Field Capacity Moisture Research Articles

Phyto-extraction ability of <i>Digitaria exilis</i> (Fonio) to heavy metals

Among the different contaminants in the environment, heavy metals are unique due to the fact that they cannot be broken down to non-toxic forms. The research was conducted to determine the remediation potential of Digitaria exilis and to identify the varieties that can tolerate heavy metals contamination. Soil was collected in an Automobile mechanic workshop, Government Reserved Area (GRA) Ado-Ekiti. Five kilograms (5 kg) of soils collected was air dried, sieved and filled into plastic buckets. The experiment was a completely randomized designed with three replicates. Three different accessions of Digitaria exilis namely; Jakah D Iburua (JAK), Dinat D Iburua (DID) and Jiw D Iburau (JIW) were planted. Soils were watered till field moisture capacity. Plant height was determined every two weeks after planting. Soil analysis was carried out to determine the physical and chemical properties before and after the experiment. Heavy metals including Cd, Fe, Zn, Pb, As and Cu were determined in the plant roots and shoots using Atomic Absorption Spectrophotometer (AAS). Accession JAK Bio-accumulated heavy-metals in their root than shoot, consequently, significant high plant height was recorded. However, shoot of accession JAK accumulated 22 % Pb, 46.78% Cu and 37.5% Cd and 20.3% Zn than others whereas accession DID accumulated As than accession JAK. Therefore, accession JAK demonstrated highest phyto-extraction of heavy-metals potentials at the root. Variety JIW has the lowest plant height, root and shoots heavy metals accumulation. Although heavy metals contaminated soil affected the growth of D. exilis, nevertheless accession JAK has the highest productivity under this condition and can be further recommended in phyto-extraction of heavy-metals in polluted sites.Keywords: Phyto-extraction, Digitaria exilis and Heavy-metals

Application of three nanoparticles (Al2O3, SiO2 and TiO2) for metal-contaminated soil remediation (measuring and modeling)

The immobilization of zinc (Zn), cadmium (Cd) and nickel (Ni) using nanoparticles (NPs) was investigated. Two non-calcareous and calcareous contaminated soils were incubated with Al2O3, SiO2 and TiO2 at 1 and 3% wt for 30 days at 25 °C in field capacity moisture and then were fractionated by the sequential extraction procedure. After application of NPs, a significant increase in metals was observed in residual (RES) fraction. The maximum reduction in exchangeable (EXC) Cd fraction was measured in soil treated with 1% Al2O3 (38.3%) and 3% SiO2 (56.1%) for non-calcareous and calcareous soils, respectively. The highest decrease in EXC Zn fraction in non-calcareous and calcareous soils was 28.8% for Al2O3 (3%) and 57.1% TiO2 (3%) treatments, respectively. Interestingly, non-calcareous soil showed a higher capacity to reduce Ni in available fractions and it decreased on average by 14.0% and 11.0% for non-calcareous and calcareous soils, respectively. In general, SiO2 NPs were an effective sorbent for immobilizing three metals in calcareous soils, while in non-calcareous soils the maximum reduction in mobile fraction of Cd and Zn occurred in the presence of Al2O3 NPs, and the shift from mobile to stable fractions of Ni was higher in soils containing SiO2 NPs. Similar to experimental data, the model predicted that NPs could reduce metal in EXC, carbonate (CAR), oxide (OX) and organically bound (OR) fractions. Results suggested that NPs can be effectively used for metal immobilization in multi-metal-contaminated soils and that surface complexation modeling (PHREEQC) could describe different fractions of metal in soils.

Укорінення відсадків підщепи яблуні м.9 залежно від субстрату для підгортання

Стаття присвячена дослідженню впливу мульчуючих матеріалів на параметри кореневої системи відсадків підщепи М.9. Вирощування посадкового матеріалу для інтенсивних насаджень яблуні базується на якісному вегетативно-розмножуваному підщепному матеріалі, який отримують з відсадкових маточників. Висока ефективність маточника досягається за підгортання органічним субстратом, що сприяє поліпшенню коренеутворення, створюючи сприятливий повітряний, тепловий і водний режими біля основи пагона і істотно підвищує вкорінення відсадків. Застосування тирси сприяє розвитку кореневої системи відсадків. З метою економії, тирсою іноді роблять лише перше підгортання, надалі використовують ґрунт. Оскільки тирса вимагає щорічного поновлення, актуальним є пошук замінника і зменшення обсягів використання, зокрема застосування поліуретанових гранул. Дослідження проводили в 2012–2014 рр. в навчально-виробничому відділі Уманського національного університету садівництва. Маточник горизонтальних відсадків підщепи М.9 закладений в 2002 р оздоровленими рослинами за схемою 1,4 х 0,33 м. Вивчали вплив суміші тирси листяних порід (крім дуба) з додаванням 25, 50 або 75 % будівельних пінополістиролових гранул діаметром 0,3–0,8 см (марка "Вік буд") на розвиток кореневої системи відсадків. Встановлено, що найбільша довжина і кількість коренів відсадків М.9 досягається за першого підгортання маточних рослин пінополістироловими гранулами, перевищуючи відповідно на 21,0–62,7 % результат застосування тирси. Зі збільшенням частки гранул в суміші з тирсою показники, в основному, лінійно зростають. Довжина кореневої системи відсадків М.9 залежить від застосування субстрату (вплив фактора 92 %) з максимальним значенням за підгортання сумішшю тирси з 75 % пінополістиролових гранул.

Short-term Influence of Organic Matter and Saline Water on Inorganic Soil Phosphorus Transformation in Barisal and Dumuria Soil Series of Bangladesh

A laboratory incubation experiment was carried out to investigate the influence of soil salinity and organic matter on inorganic phosphorus transformation with times in two different soil series such as Barisal and Dumuria located in Ganges Tidal Floodplain sites of Bangladesh. Two representative soil samples were collected from surface soil (0-15 cm) with composite sampling. The salinity and organic matter treatments were 4 dS m-1 and 5 t ha-1 (decomposed cow dung) with three replications. The treated soils were then incubated in the laboratory at field capacity moisture condition. To determine the transformation of different forms of inorganic P, sampling was done for 0, 7, 15 and 30 days. Different forms of inorganic P such as soluble and exchangeable phosphorus (SE-P), iron and aluminium bound phosphorus (Fe and Al-P), calcium bound phosphorus (Ca-P) and residual phosphorus (RE-P) were determined at different days of incubation. For Barisal soil series, the sequence of different forms of inorganic P was Ca-P>RE-P>Fe and Al-P>SE-P according to their amount. For Dumuria soil series, the sequence was Ca-P>RE-P>Fe and Al-P>SE-P, respectively. The sequence clearly indicates that the soluble and exchangeable P increases with time due to a combination of salinity and decomposed organic matter which increases the uptake of P and ultimately increases the yield. The changes were statistically significant (P < 0.001) in the case of all three soils.

Наукові основи адаптивної технології вирощування стевії в Україні

Наукові основи адаптивної технології вирощування стевії в Україні

Changes in recovery of native and applied phosphorus with time as affected by soil properties in some calcareous soils

ABSTRACTIn an attempt to investigate variations in availability of native and applied phosphorus (P) with time, twenty five calcareous soil samples were treated with 0, 50 and 500 mg P kg−1 soil and incubated at 80–90% of field capacity moisture content in an open door glasshouse for a period of one year. Soil samples were taken out at certain intervals for P extraction with Olsen extractant under moist condition. Results indicated that following wetting the mean value of native Olsen-P decreased initially and then increased gradually with time of incubation. Generally, the short term (24 h) recoveries were not correlated with long term ones. The recovery of added P with time was described properly by the following new proposed model: R = 100/(1 + ktb), where R is percent recovery at time t, and k and b are empirical parameters. The values of k constant at 50 and 500 mg P kg−1 were in the ranges of 0.40 to 1.22 (0.84 ± 0.25, on average) and 0.04 to 0.52 (0.23 ± 0.14, on average), respectively. The corresponding respective values of b constant also ranged from 0.05 to 0.32 (0.15 ± 0.06, on average) and 0.12 to 0.92 (0.46 ± 0.23, on average).

Survival of Acidovorax citrulli in infected melon tissues and in different edafoclimatic conditions

Abstract The survival of Acidovorax citrulli Aac1Rif was accessed in infected melon tissues (fruits and leaves) incorporated to the soil at 0, 5, 10 and 15 cm depth, in seven different types of soil, at temperatures 10, 15, 20, 25, 30 and 35 ºC and moisture field capacity of 50 and 100% in the absence of the host plant. Aac1Rif was detected in melon tissues at 0, 5 and 10 cm until 21 days and at 15 cm until 14 days. The highest and lowest relative extinction rate of the population (RERP) for Aac1Rif occurred respectively in fruit tissues and leaf tissues at depths of 0 and 5 cm. Aac1Rif survived in seven types of soil only for three days. The lowest RERP occurred at 10 or 15 ºC and the highest at 30 or 35 ºC. Greater concentrations of Na+, silt, and greater populations of actinomycetes and Trichoderma were correlated with highest RERP of the Aac1Rif in the soil. There was significant difference between RERP at 100% and 50% of field capacity. The soil was not considered potential primary source of A. citrulli inoculum. Infected melon fruits and leaves in soil were considered as such sources, at least for 21 days.

Balangu (Lallemantia sp.) growth and physiology under field drought conditions affecting plant medicinal content

Drought stress is one of the most important stresses adversely affecting plant growth and yield production. Due to the importance of global warming, the investigation of drought effects on the growth and quality of medical plants is of vital importance. Accordingly, a two-year field experiment was conducted in 2013–2014 to determine the effects of drought levels and plant species on Balangu (Lallemantia sp.) growth and physiological properties including medicinal content. The experiment was a split plot in which the drought levels (main plots) including control (D1, moisture field capacity, water potential at, 0.5 atm), moderate stress (D2, 6.5 atm) and severe stress (D3, 9.5 atm), and the Balangu species (sub plots) including Lallemantia royleana (Benth) (L1) and L. iberica (L2) were tested as the experimental treatments. Plant yield, oil content and the biochemical properties (i.e. medicinal content) including phenolic compounds, proline, carotenoids, and the activity of antioxidant enzymes including peroxidase (EC 1.11.1), super oxide dismutase (SOD, EC 1.15.1.1)) and ascorbate peroxidase (APX, EC 1.11.1.11) were determined. Drought stress significantly decreased crop yield and oil content. However, the production of phenolic compounds and proline as well as the activity of antioxidant enzymes, SOD and APX increased under stress. The species L2 was the more tolerant species under drought stress. The interesting point about this research work is the increased production of secondary metabolites (i.e. phenolic compounds) under stress, affecting both Balangu response and medicinal properties. Accordingly, it may be possible to regulate the production of secondary metabolites (medicinal contents) in Balangu species by adjusting the irrigating practices.

Soil Moisture Availability at Early Growth Stages Strongly Affected Root Growth of Bothriochloa ischaemum When Mixed With Lespedeza davurica.

Rainfall is the main resource of soil moisture in the semiarid areas, and the altered rainfall pattern would greatly affect plant growth and development. Root morphological traits are critical for plant adaptation to changeable soil moisture. This study aimed to clarify how root morphological traits of Bothriochloa ischaemum (a C4 herbaceous species) and Lespedeza davurica (a C3 leguminous species) in response to variable soil moisture in their mixtures. The two species were co-cultivated in pots at seven mixture ratios under three soil water regimes [80% (HW), 60% (MW), and 40% (LW) of soil moisture field capacity (FC)]. At the jointing, flowering, and filling stages of B. ischaemum, the LW and MW treatments were rewatered to MW or HW, respectively. At the end of growth season, root morphological traits of two species were evaluated. Results showed that the root morphological response of B. ischaemum was more sensitive than that of L. davurica under rewatering. The total root length (TRL) and root surface area (RSA) of both species increased as their mixture ratio decreased, which suggested that mixed plantation of the two species would be beneficial for their own root growth. Among all treatments, the increase of root biomass (RB), TRL, and RSA reached the highest levels when soil water content increased from 40 to 80% FC at the jointing stage. Our results implied that species-specific response in root morphological traits to alternated rainfall pattern would greatly affect community structure, and large rainfall occurring at early growth stages would greatly increase their root growth in the semiarid environments.

Effects on soil phosphorus dynamics of municipal solid waste compost addition to a burnt and unburnt forest soil

The main aim of this research was to assess the effects of municipal solid waste compost (MSWC) addition to a burnt and unburnt calcareous soil, on the distribution of soil P forms in particle-size and extractable fractions. Three MSWC doses (1, 2 and 4% w/w) were added to burnt and unburnt soil samples and were incubated for 92 days at 29 °C and 75% of field capacity moisture. A particle-size fractionation followed by a sequential P extraction procedure was carried out. The burnt soil showed significantly lower concentrations of organic P forms (Porg) and significantly higher concentrations of stable P forms than the unburnt soil. Besides, in both burnt and unburnt soils, most P-forms presented higher concentrations in the clay fractions than in the sand and silt fractions, possibly due to the different proportions of microbial synthesized and plant-derived substances in the different particle-size fractions. Finer fractions of MSWC showed higher total P and Porg concentrations than coarser fractions. Our results showed that the highest dose of MSWC` was the most effective one for the rehabilitation of the burnt soil. MSWC amendment also caused an increase in soil P availability in the unburnt soil which initially contained relatively low levels of P. During the incubation process, a high proportion of organic P contained in the MSWC was mineralized into inorganic P forms. These forms were precipitated with Ca cations which are very abundant in these calcareous soils, significantly increasing the P fraction extracted by HCl in both amended soils. Hence, adding compost to the soil involved an increase in the available P reservoir in the long term. The combination of particle-size fractionation, chemical sequential extraction and incubation experiments can be a valuable tool for splitting soil phosphorus into different fractions regarding their availability in relation to short and long-term transformations in soil.

THE ECONOMY OF WATER RESOURCES WITH THE USE OF POLYMER COMPLEXES IN IRRIGATION OF A COTTON

The article deals with the use of polymer complexes in alluvial-meadow soils under the pre-determined humidity of 70-80-65% of the maximum field moisture capacity, in the second option with the 1-2-1 scheme in the Bukhara oasis. During the seedling and flowering phase, one irrigation irrigation norm was performed at 734 m3/ha; during the blooming and fruit cultivation phase, three irrigation operations were performed with irrigation norms of 631-644 m3/ha, one irrigation with a watering rate of 865 m3/ha was performed during the maturation phase. The irrigation norm was 2874 m3/ha or, relative to the control variant, by 1754 m3/ha less, which allowed saving manual water, as well as the results of the conducted experiments and their impact on cotton growth, development and yield.

Spatial variability of soil physical properties in Archeological Dark Earths under different uses in southern Amazon

The Amazon region has soils of an anthropic formation called Anthropogenic Dark Earths (ADEs). These soils present a higher fertility and are physically different to adjacent local soils. This study aimed to investigate the conditions and spatial behavior of soil physical attributes in ADE areas cultivated with cocoa, coffee, and grassland in southern Amazon. Mapping of three ADE areas was carried out by using sampling grids of 80 m × 56 m with regular spacing of 8 m for the grassland area and 48 m × 88 m with a spacing of 6 m × 8 m for the cocoa and coffee areas. These soils were sampled at the grid crossing points at depths of 0.00–0.05; 0.05–0.10 and 0.10–0.20 m, totaling 88 points in each area. Soil physical analyses of texture, macroporosity, microporosity, total porosity, bulk density, θFC (moisture field capacity), penetration resistance, and aggregate stability were carried out. The data were submitted to descriptive statistics, geostatistics, and multivariate statistics. In the ADE area cultivated with grassland, the attributes showing moderate and weak levels of spatial dependence were those with a greater spatial continuity, i.e. texture, penetration resistance, macroporosity, microporosity, and volumetric moisture. A similar behavior was observed in the ADE areas cultivated with coffee (sand, density, penetration resistance, macroporosity, and microporosity) and cocoa (silt, clay, penetration resistance, macroporosity, and mean weight diameter of aggregates).

Effect of light on persistence of imidacloprid in soil

Imidacloprid are Applied Widely to Protect Crops from Damage by Insect Pest, the Residue Usually Come Into Contact with Soil, where They Undergo A Transformations That Lead to Formation of A Complex Pattern of Metabolites. This Study Was Performed to Study The Persistence And Degradation Of Imidacloprid In Gezira-Sudan Soil As Affected By UV And Sunlight Exposure.The High-Performance Liquid Chromatography (HPLC-DAD) Were Used To Characterize The Photodegradation Kinetics Under The Experiment Condition And To Identify The Main Photoproducts IMI-Urea In Soil Samples As To Propose Plausible Photodegradation Pathways Of Imidacloprid In Soil.Samples Of Soil Were Placed In Petri-Plate, Brought To Field Capacity Moisture And Then Exposed To UV And Sunlight. Residues Of Imidacloprid In Soil Dissipated With Half-Life Of 15.84 Under UV And 60.2 Days Under Sunlight. Exposure Of Thin Film Of Imidacloprid To UV And Sunlight Confirmed That It Is Photo Labile And Dissipated Very Fast With Half-Life 15.05 And 8.6 Days Under UV And Sunlight, Respectively. The Formation Of Imidacloprid-Urea As Main Photoproduct Was Only Detected On Day 7 In The Case Of Thin-Film Exposed To UV-Light. The Study Revealed That UV Component Of Sunlight Is An Important Factor For Imidacloprid Dissipation From Soil Surface.

The water consumption of white cabbage that cultivated under drip irrigation on the cis-volga districts of Saratov Region

Field research was realized in 2014-2016. The following thesis presents the results of the effect of drip irrigation and calculated doses of mineral fertilizers on the productivity of breeds of white cabbage when grown in the Chernozem steppe of Saratov Cis-Volga region. The field ex-periment was laid  down by the method of split plots with three replications on the area of 30 m2. It is was founded that the yield increase of cabbage breed “Amager 611” due to the improved water regime is 4.7–5.7 % compared to the control; due to the improved nutritional regime – 11.1–23.4 %; the yield increase of cabbage hybrid “Kolobok” respectively 10.1 – 19.1 and 11.7% – 31.5%. The water consumption characteristics of crop were defined for the first time for the Saratov Cis-Volga region: total water consumption is 5254.5 – 5712.5 m3/ha, and it in-crease with increasing pre-irrigation soil moisture; a major share in water consumption is irrigation water, which accounts for 52.1-56.3%. The crop consumes the greatest amount of moisture (from 83.8 to 87.6 percent of total water consumption) during the period from the beginning of curling to the technical ripeness of head. Average daily water consumption during the growing season ranges is from 44.53 to 49.03 m3/day. The dependences of the yield of white cabbage that cultivated on the southern chernozem due to joint action of water and fertilizers has the forms: for the «Amager 611» breed Y = –578 + 0.037·DNPK + 0.497·M + 9.901·10-5· DNPK2 – 8.552·10-6· DNPK ·M – 9.244·10-5·M2; for the «Kolobok» hybrid Y = –406 + 0.035· DNPK+ 0.312·M + 1.455·10-4· DNPK2 – 1.361·10-5· DNPK·M – 5.323·10-5·M2 (n of 0.53 and 0.54 respectively). The highest yield of the crop (94.25 t/ha) was obtained by cultivation of the «Amager 611» breed, with the maintenance of the regime of drip irrigation 80% of the field moisture capacity in the 0.3 m layer before the curling of heads and 0.5 m layer after the curling, and the introduction of mineral fertilizers in the dose of N190P80K70.

LOCAL IRRIGATION METHODS FOR VEGETABLE PRODUCTION IN SOUTH OF RUSSIA

In the Southern Federal District, where the Volgograd region occupies a significant territory, cultivation of vegetable crops is impossible without irrigation. There was a large number of wide-spread sprinklers in the USSR. Each unit of this system watered at least 60 to70 hectares, required a lot of water pressure that resulted in high operating costs. Therefore, currently, such local irrigation methods as drip and subsoil irrigation have a broad development perspective. Both irrigation methods favorably differ from sprinkling by a significant increase in yield of vegetable crops, irrigation water saving, ease of operation and rapid investment return. In this regard, the main goal of our research, conducted at Volgograd State Agricultural University, is development of techniques and technologies for drip and subsoil irrigation that allow receiving projected vegetable yields while maintaining soil fertility and environmental safety. The research have shown that it is possible to obtain planned yields of 60, 70 and 80 t/ha of zucchini and table beet using drip irrigation in steppe zone of southern Russia on light chestnut soils. Therefore, it is necessary to observe irrigation regimes with maintaining pre-irrigation moisture (PIM) 75-85-75 and 85% of field moisture capacity (FMC) simultaneously with application of calculated doses of mineral fertilizers. Moreover, it is important to apply increased doses of mineral fertilizers with decrease in intensity of irrigation regime due to reduction in soil moisture content to 75% of FMC. The planned radish yield of 80 tons per hectare with subsoil irrigation can be obtained in variants with differentiated soil moisture 75-85-75% of FMC and 1.4 m distance n t between humidifiers, and also maintaining constant soil moisture at 85% of FMC at plots with 1.2 and 1.4 m distances.

Effect of Incubation Duration of Incorporated Organics on Saturated Hydraulic Conductivity, Aggregate Stability and Sorptivity of Alluvial and Red-Laterite Soils

Improvement in soil hydro-physical properties is a pre-requisite for maintaining soil quality and sustaining agricultural productivity. The objective of this study was to see the effect of degree of decomposition of farmyard manure (FYM) and vermicompost on aggregation indices viz., water stable aggregate (WSA), mean weight diameter (MWD) and aggregate stability (AS), and water transmission properties namely, saturated hydraulic conductivity (Ks) and sorptivity (S) of two contrasting soils (red-laterite and alluvial soils). Soils were incubated with FYM and vermicompost @ 20 t ha−1 for 60 days at field capacity moisture content under laboratory condition and analyzed at 0, 20, 40 and 60 days of incubation (DOI) for hydrophysical and soil organic carbon (SOC) content. Results indicated that the influence of organics was more predominant in red-laterite soil having more iron and aluminium oxides and lower clay content than alluvial soil. Upon incubation, the organic treated red-laterite and alluvial soils increased 73 and 15 per cent SOC, 16 and 13 per cent micro-porosity, 119 and 412 per cent Ks, 25 and 19 per cent WSA, 45 and 11 per cent MWD and 31 and 26 per cent S, respectively. Similarly, vermicompost and FYM treated soils increased 44 and 43 per cent SOC, 17 and 11 per cent micro-porosity, 622 and 239 per cent Ks, 31 and 13 per cent WSA, 33 and 24 per cent MWD and 46 and 11 per cent S. Bulk density (BD) varied from 1.54 to 1.38 and 1.31 to 1.24 Mg m−3, respectively for red-laterite and alluvial soils during the entire incubation period with a strong negative relationship (r =-0.97, p< 0.001) with micro-porosity. Strong positive correlations between WSA and SOC (r = 0.58, p < 0.01), MWD and SOC (r = 0.74, p < 0.001) and AS and SOC (r = 0.73, p < 0.001) were observed indicating that the AS would increase 3.8 per cent with the increase in SOC by 1% in both soils. Sorptivity was positively and significantly related to SOC (r = 0.55, p<0.01) and micro-porosity (r = 0.51, p<0.01), however, had a negative relationship with BD (r =-0.51, p<0.01). Vermicompost had shown better results in structural as well as hydro-physical properties as compared with FYM in both soils.

Влияние осушения и применения минеральных удобрений на урожайность яровой пшеницы

The article provides the results of the research carried out in 2012-2017. Studied was the elfect of drainage and various rates of mineral fertilizers on the productivity of spring wheat, the water-physical properties of the soil, the nutritive regime, biological activity, photosynthetic activity, payback from 1 kg of active ingredient by increase in the yield in the Tver region. The experiment is laid on drained soil with closed drainage and non-drained sod-podzolic light loamy soil in three variants: 1 - without fertilizers, 2 - N 45 P 45 K 45 , 3 - N 90 P 9Q K 90 . The greatest differences in the water-air regime on these soils were observed in the moisture content of the arable layer and the porosity of aeration. On the average, for 6 years of vegetation on the drained soils they accounted for 65% of the field moisture capacity and 28% of the soil volume, on non-drained soils - 85 and 21% respectively. The use of fertilizers and the increase in their rates had a positive effect on the content of nitrate and ammonia nitrogen in the plow layer of the soil in both areas without distinct differences in them. Dehumidification and application of fertilizers had a favorable effect on the photosynthetic activity and, in general, on the formation of the crop. Leaf area in the 1st and 3rd variants of the experiment, the photosynthetic potential differed 2.3-2.9 times on the plots. On the drained lands, on the average, by the variants of the experiment they were higher by 28 and 31% respectively. In terms of fertilizer options, on the average, the yield of spring wheat in the drained area was more than 0.61 / ha. In the second variant of fertilizers, compared to the background without using them, the yield increased by 60% in the drained area, and by 57% in the non-drained area, and the increase in the fertilizer rate ensured an increase on the plots by 16% and 21%, respectively. The largest payback from 1 kg of active ingredient by the yield was recorded on both plots as the result of N 45 P 45 K 45 application - 9.8 kg of grain on drained plot and 7.9 on non-drained one.

Fruit quality components of balsam pear (Momordica charantia L.) and soil respiration in response to soil moisture under two soil conditions

Balsam pear (Momordica charantia L.) is an important vegetable reported to have pharmacological properties. It contains abundant bioactive compounds which can be affected by viticulture and environment factors. Identification of the optimal cultivate condition is fundamental to enhance fruit quality components of balsam pear and to decrease carbon dioxide efflux of vegetable garden. The objective of this study was to identify changes of health-promoting bioactive compounds (flavonoids and saponins) and fruit nutritional quality of balsam pear, as well as seasonal variation of soil respiration (Rs) in response to soil moisture under different soil types. A field experiment was conducted using a 3 × 2 factorial involving three levels soil moisture including 50–60% (L), 70–80% (M), and 90–100% (H) of field moisture capacity (FC) under Loessial soil (L) and Cumulic cinnamon soil (C) conditions. The results indicated that moderate soil moisture was benefit for improving quality components, 70–80% FC was benefit for accumulation of health-promoting bioactive compounds on the Cumulic cinnamon soil, and 70–80% FC was benefit for the nutritional quality of fruit on the Loessial soil; soil respiration measured in Loessial soil were always higher than that in Cumulic cinnamon soil. Air temperature, photosynthetic active radiation, soil temperature had positive correlation with Rs to some extent, while air relative humidity had a negative correlation with Rs. This study would be potentially beneficial for efficiently producing functional and high quality balsam pear.

Basil (Ocimum basilicum L.) water needs calculated from the crop coefficient

The determination of the crop coefficient (Kc) throughout the phenological stages is important for the calculation of water requirements of plants. This study determined the Kc curve for Basil (Ocimum basilicum L.) in Candelaria, Valle del Cauca, and evaluated this Kc in greenhouse conditions. Three drainage lysimeters and a portable meteorological station were used to determine the reference evapotranspiration (ETo), which were set up randomly in an experimental plot. The field capacity (FC) moisture content was determined, and the soil moisture and drainage depth were periodically monitored. Daily water balance calculations were conducted to determine the crop’s water needs (ETc), and the Kc was calculated based on the quotient between ETc and ETo by performing statistical regression analysis. In the second experiment, in a completely randomized bifactorial design, four treatments were established in Cali (Valle). These treatments were amount of water necessary to maintain the soil moisture at FC and amount of water calculated with the Kc (72 % FC), both treatments with and without fertilizers application. The results showed that the Kc values for basil are: growth stage, 0,45 ± 0,02 (25 days after transplant, dat); maturity stage, 0,59 ± 0,02 (26 – 50 dat); and senescence stage, 0,42 ± 0,03 (51 – 71 dat). In greenhouse conditions, dry mass percentage, plant height, soil pH and electrical conductivity were similar for both water regimens. The reduction on water with Kc increased the nitrogen foliar but the water use efficient decreased.

Physiological and antioxidant responses of winter wheat cultivars to strigolactone and salicylic acid in drought

Strigolactones are considered as important regulators of plant growth and development. Recently positive regulatory influence of strigolactones in plant in response to drought and salt stress has been revealed. Salicylic acid, a phytohormone, has reported to be involved in a number of stress responses such as pathogen infection, UV irradiation, salinity and drought. Considering the concealed role of strigolactones in agronomic crops drought tolerance and possible interaction among salicylic acid and strigolactone, we investigated the effects of exogenous application of GR24 and salicylic acid on two winter wheat cultivars under drought conditions. Foliar GR24 and salicylic acid were applied on drought sensitive and drought tolerant winter wheat cultivars at tillering and anthesis stages in 40% and 80% of field capacity moisture levels. Strigolactones and salicylic acid treated plants showed higher tolerance to drought stress with regard to lower electrolyte leakage and higher relative water content, leaf stomatal limitation, membrane stability index and antioxidant enzyme activities. Salicylic acid application dampened malondialdehyde content in wheat plants. Drought tolerance of wheat plants were intensified in most of the cases when theses phytohormones were used together, suggesting a possible interaction between salicylic acid and strigolactones in drought situations.