Abstract. The high erosion rates found in the agriculture land make valuable the use of mulches to control the soil and water losses. Coffee husk (Coffea canephora var. robusta) can be one of those mulches. This paper evaluates how to apply the mulch in order to obtain the best effectiveness. An experimental factorial design 4 × 3 × 2 with two replicates was designed in a greenhouse with a total number of 48 cases. All the samples were deposited in trays of 0.51 m 2 and applied a simulated rain of 122 mm h −1 during 21 min. The factors examined were the following: four soil classes; three treatments -buried (B), surface (S) and non-residue (C) -and the presence (WC) or absence (WOC) of the soil surface crusting. The coffee husk residue (S and B treatments) reduced runoff by 10.2 and 46 % respectively, soil losses by 78.3 and 88.7 % and sediment concentration by 77 and 84.4 %. The infiltration rate increased on average by 104 and 167 %, and time to runoff by 1.58 and 2.07 min respectively. Coffee husk is an efficient mulch to reduce the soil and water losses, although it could not completely cushion the influence of crust.

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Purpose The demand of rice by the increase in population in many countries has intensified the application of pesticides and the use of poor quality water to irrigate fields. The terrestrial environment is one compartment affected by these situations, where soil is working as a reservoir, retaining organic pollutants. Therefore, it is necessary to develop methods to determine insecticides in soil and monitor susceptible areas to be contaminated, applying adequate techniques to remediate them. Materials and methods This study investigates the occurrence of ten pyrethroid insecticides (PYs) and its spatio-temporal variance in soil at two different depths collected in two periods (before plow and during rice production), in a paddy field area located in the Mediterranean coast. Pyrethroids were quantified using gas chromatography-mass spectrometry (GC-MS) after ultrasound-assisted extraction with ethyl acetate. The results obtained were assessed statistically using non-parametric methods, and significant statistical differences (p < 0.05) in pyrethroids content with soil depth and proximity to wastewater treatment plants were evaluated. Moreover, a geographic information system (GIS) was used to monitor the occurrence of PYs in paddy fields and detect risk areas. Results and discussion Pyrethroids were detected at concentrations ≤57.0 ng g −1 before plow and ≤62.3 ng g −1 during rice production, being resmethrin and cyfluthrin the compounds found at higher concentrations in soil. Pyrethroids were detected mainly at the top soil, and a GIS program was used to depict the obtained results, showing that effluents from wastewater treatment plants (WWTPs) were the main sources of soil contamination. No toxic effects were expected to soil organisms, but it is of concern that PYs may affect aquatic organisms, which represents the worst case scenario. Conclusions A methodology to determine pyrethroids in soil was developed to monitor a paddy field area. The use of water from WWTPs to irrigate rice fields is one of the main pollution sources of pyrethroids. It is a matter of concern that PYs may present toxic effects on aquatic organisms, as they can be desorbed from soil. Phytoremediation may play an important role in this area, reducing the possible risk associated to PYs levels in soil.

Sánchez Brunete, C.; Albero, B.; Moreno-Ramón, H.; Tadeo, JL. (2017). Pyrethroids levels in paddy field water under Mediterranean conditions: measurements and distribution modelling. Paddy and Water Environment. 15(2):307-316. Abstract 14The cultivation of rice (Oriza sativa L.) under Mediterranean conditions regularly requires the use of 15 treated wastewater due to shortage of freshwater. As a consequence, the intensification of rice production 16 to supply the uprising demand of grain could break the stability between agriculture and environment. In 17 this work, we studied the occurrence and distribution of pyrethroids in surface water and groundwater 18 collected during two periods (flooding and dry soil conditions) in paddy fields located in the Spanish 19Mediterranean coast. Pyrethroids were detected at concentrations ranging from 14 to 1450 ng L-1 in 20 surface water and from 6 to 833 ng L-1 in groundwater. The results obtained were evaluated statistically 21 using principal component analysis, and differences between both sampling campaigns were found, with 22 lower concentrations of the target compounds during the flooding sampling event. Moreover, a 23 geographic information system program was used to represent a model distribution of the obtained 24 results, showing wastewater treatment plants as the main sources of contamination and the decrease of 25 pyrethroids during flooding condition when water flows over the paddy fields. The impact of these 26 compounds on water quality was discussed. 28 Introduction 30Water is the main limiting factor to produce rice in Mediterranean countries because they are located in 31 arid or semiarid regions. Thus, due to the shortage of freshwater, wastewater has been used in the last 32 decades to fulfill water needs of rice cultivation (Rodríguez-Liébana et al. 2014). The most prevalent risks 33 associated with the use of these poor quality waters are: pH, salinity, pathogens, heavy metals and organic 34 chemicals (Albalawneh et al. 2015). 35The presence of pesticides in irrigation water is one of stressors that aquatic organisms face (Smiley et al. 362014), pointing out the interest of the relationship between biodiversity and agriculture (Swift et al. 372015). In particular, the use of pyrethroids (PYs) has increased in the last years as a replacement for 38 organophosphates, which had already substituted organochlorine compounds, due to their relatively lower 39 mammalian toxicity and lower environmental persistence. Although the application of PYs in rice fields 40 is scarce and needs individual authorization, they are extensively used in urban and industrial areas and 41 livestock farms to control pests such as mosquitoes and lice. Several studies report that these compounds 42 are not completely eliminated in conventional wastewater treatment plants (WWTPs) (Campo et al. 2013; 43 Weston et al. 2013), and thus they can be introduced into the environment through WWTPs effluents. 44Pyrethroids have raised concern because they may have a negative impact on the ...

The cultivation system with cover crops as living mulches is growing in importance in the worldwide agriculture as it combines an economical effect with pro-ecological and soil protecting activities. The plant species tested in the research were not frost resistant: buckwheat, millet, white mustard and berseem clover. A control were the plots without cover crops. The intercrops were sown in the first decade of August, in autumn a grown biomass was a living mulch, and after being damaged by frost in spring, the mulch was covering ground surface. Winter garlic bulbs were planted in grown biomass of cover plants, in the first decade of September. In the first decade of November and in the first decade of April, the selected soil parameters were determined in the soil layer of 0-10 cm: actual soil moisture (%), soil bulk density (Mg • m-3), total porosity (%) and water stability of soil aggregates (%). The harvest of garlic was conducted in the first decade of July. Cover crops mulches had an influence on soil physical properties. In spring, the soil from plots with cover crops mulching characterized with the highest moisture, higher total porosity and soil aggregates stability as well as lower soil bulk density. In comparison to the control cultivation of winter garlic, without cover crops, the effect of plants used for mulching on marketable yield was not observed. Garlic plants intercropped with the white mustard mulch formed leaves and bulbs of higher weight in comparison to cultivation without cover crops.

Abstract. The high erosion rates found in the agriculture land make valuable the use of mulches to control the soil and water losses. Coffee husk (Coffee canephora var. robusta) can be one of those mulches. This paper evaluates how to apply the mulch in order to obtain, with the same doses, the best effectiveness. An experimental factorial design 4 × 3 × 2 with two replicates was designed in a greenhouse with a total amount of 48 treatments. All the samples were deposited in trays of 0.51 m2 and applied a simulated rain of 122 mm h−1 during 21 min. The factors examined were: four soil classes; three treatments: buried (B), surface (S) and non-residue (C), and the presence (WC) or absence (WOC) of the soil surface crusting. The coffee husk residue (S and B treatments) reduced runoff by 10.2% and 46% respectively, soil losses by 78.3% and 88.7% and sediment concentration by 77% and 84.4%. The infiltration rate increased on average by 104% and 167%, and time to runoff by 1.58 and 2.07 min respectively. The coffee husk mulch (S and B) avoided the influence of crust. Coffee husk is an efficient mulch to reduce the soil and water losses.

Climate change accentuates abiotic stress conditions putting at risk several commercial cultivars particularly vulnerable to salinity in the early stages of development, which makes adopting new technologies in tune with the environment necessary to mitigate its impact. In this study, we tested the possible effects of a commercial biostimulant (BALOX®) on enhancing salt stress tolerance in salt-treated tomato plants, analysing plant growth and several stress biochemical markers: photosynthetic pigments, ion contents in roots and leaves, leaf concentrations of different osmolytes, oxidative stress markers, non-enzymatic antioxidants, and the specific activities of major antioxidant enzymes. The experimental design consisted of three soil salinity levels (non-saline, saline, and very saline), two biostimulant doses (0.4 mL and 0.8 mL of the BALOX® stock per litre of irrigation water), and the non-treated control (without biostimulant), evaluated at 30 and 60 days of treatment. The biostimulant favoured plant growth, especially at the root level and in saline soils. In addition, it helped reduce Na+ and Cl− uptake by the roots and seemed to stimulate, to some extent, K+ and Ca2+ transport to the aerial part of the plant. The BALOX® application significantly reduced the level of stress affecting the plants in saline soils, as shown by the decrease in the contents of proline and oxidative stress biomarkers and the activity of salt-induced antioxidant enzymes. Some of the biostimulant effects were also observed under low salinity conditions; therefore, in addition to enhancing salt stress responses, BALOX® appears to stimulate the growth of tomato plants through a general improvement of photosynthesis and primary metabolism.