Use Efficiency of Cyanobacteria and Olive Vegetation Water (Cyano/Ovw) Biofertilizer for Olive Trees under Different Mineral Npk Levels

2016 ◽  
Vol 43 (1) ◽  
pp. 77-107
Keyword(s):  
Use Efficiency ◽  
Vegetation Water ◽  
Olive Trees

scholarly journals Irrigation Water Use Efficiency in Olive Trees in Kairouan, Tunisia

2021 ◽  
Vol 11 (3) ◽  
pp. 255-261
Author(s):  
Hajime Kamiyama ◽  
Mohamed Kefi ◽  
Kenichi Kashiwagi
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Irrigation Water ◽  
Data Envelopment ◽  
Irrigation Water Use Efficiency ◽  
Irrigation Water Use ◽  
Use Efficiency ◽  
Olive Trees ◽  
Using Data ◽  
Scale Of Operation

This study evaluated the technical efficiency and irrigation water use efficiency of olive farms in Tunisia, using Data Envelopment Analysis. In order to calibrate and validate the findings, data related to area, water use, water quality, cultivar, input, and yield were collected based on interviews from 45 irrigated olive farms in Kairouan Governorate. The results show that average input-oriented water use efficiency under the CRS and VRS specifications is 17.2% and 36.3%, respectively, indicating that the sampled olive farms could reduce the use of water by an average of 82.8% and 63.7% by improving the performance of irrigation systems. Also, it was found that there are large differences in irrigation water use efficiency between the CRS and VRS specifications. Consequently, this indicates that a number of olive farms can enhance overall efficiency by improving the scale of operation. In practical terms, this study provides significant insights for the olive growers in this study regarding the importance of removing scale inefficiency. Specifically, they need to consider the effects of water and soil quality on irrigated fields to improve the efficiency of irrigation water use.

scholarly journals Potassium Starvation Increases Stomatal Conductance in Olive Trees

HortScience ◽  
2006 ◽  
Vol 41 (2) ◽  
pp. 433-436 ◽  
Author(s):  
Octavio Arquero ◽  
Diego Barranco ◽  
Manuel Benlloch
Keyword(s):  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
Water Use ◽  
Shoot Growth ◽  
Stomatal Closure ◽  
Agricultural Practices ◽  
Potassium Starvation ◽  
K Deficiency ◽  
Use Efficiency ◽  
Olive Trees

The effects of potassium (K) status and water availability in the growth medium on growth, water content, water-use efficiency and stomatal conductance was studied in mist-rooted `Chemlali de Sfax' olive (Olea europaea L.) cuttings grown in a perlite substrate. Potassium starvation produced dehydration of all parts of the plant, reduced shoot growth and water-use efficiency. By contrast, K starvation enhanced stomatal conductance in well-irrigated plants and, even more, in water-stressed plants. These results suggest that moderate K deficiency in olives may impair the plant's ability to regulate stomatal closure; this may account for the dehydration observed in K-starved plants, particularly in situations of water stress. This result is of great importance for agricultural practices of this crop, because K status, which may not be considered deficient, can cause disorders in olive trees.

Climate and vegetation water use efficiency at catchment scales

2009 ◽  
Vol 23 (16) ◽  
pp. 2409-2414 ◽  
Author(s):  
Peter A. Troch ◽  
Guillermo F. Martinez ◽  
Valentijn R. N. Pauwels ◽  
Matej Durcik ◽  
Murugesu Sivapalan ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Use Efficiency ◽  
Vegetation Water

scholarly journals Catchment-scale groundwater recharge and vegetation water use efficiency

2018 ◽  
Author(s):  
Peter A. Troch ◽  
Ravindra Dwivedi ◽  
Tao Liu ◽  
Antonio Alves Meira Neto ◽  
Tirthankar Roy ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Land Surface ◽  
Root Zone ◽  
Estimation Method ◽  
Catchment Scale ◽  
Use Efficiency ◽  
Vegetation Water ◽  
Recharge Rates

Abstract. Precipitation undergoes a two-step partitioning when it falls on the land surface. At the land surface and in the shallow subsurface, rainfall or snowmelt can either runoff as infiltration/saturation excess or quick subsurface flow. The rest will be stored temporarily in the root zone. From the root zone, water can leave the catchment as evapotranspiration or percolate further and recharge deep storage. It was recently shown that an index of vegetation water use efficiency, the Horton index (HI), could predict deep storage dynamics. Here we test this finding using 247 MOPEX catchments across the conterminous US. Our results show that the observed HI is indeed a reliable predictor of deep storage dynamics. We also find that the HI can reliably predict the long-term average recharge rate. Our results compare favorably with estimates of average recharge rates from the US Geological Survey. Previous research has shown that HI can be estimated based on aridity index, mean slope and mean elevation of a catchment (Voepel et al., 2011). We recalibrated Voepel’s model and used it to predict the HI for our catchments. We then used these predicted values of the HI to estimate average recharge rates for our catchments, and compared them with those estimated from observed HI. We find that the accuracies of our predictions based on observed and predicted HI are similar. This provides a novel estimation method of catchment-scale long-term average recharge rates based on simple catchment characteristics, such as climate and topography, and free of discharge measurements.

scholarly journals Effect of the water stress on gross primary production modeling of a Mediterranean oak savanna ecosystem

2018 ◽  
Vol 380 ◽  
pp. 37-43
Author(s):  
Pedro J. Gómez-Giráldez ◽  
Elisabet Carpintero ◽  
Mario Ramos ◽  
Cristina Aguilar ◽  
María P. González-Dugo
Keyword(s):  
Water Stress ◽  
Primary Production ◽  
Gross Primary Production ◽  
Weather Conditions ◽  
Oak Trees ◽  
Mediterranean Shrubs ◽  
Use Efficiency ◽  
Vegetation Water ◽  
Production Modeling ◽  
Additional Coefficient

Abstract. Dehesa ecosystem consists of widely-spaced oak trees combined with crops, pasture and Mediterranean shrubs. It is located in the southwest of the Iberian Peninsula, where water scarcity is recurrent, severely affecting the multiple productions and services of the ecosystem. Upscaling in situ Gross Primary Production (GPP) estimates in these areas is challenging for regional and global studies, given the significant spatial variability of plant functional types and the vegetation stresses usually present. The estimation of GPP is often addressed using light use efficiency models (LUE-models). Under soil water deficit conditions, biomass production is reduced below its potential rate. This work investigates the effect of different parameterizations to account for water stress on GPP estimates and their agreement with observations. Ground measurements of GPP are obtained using an Eddy Covariance (EC) system installed over an experimental site located in Córdoba, Spain. GPP is estimated with a LUE-model in the footprint of the EC tower using several approaches: a fixed value taken from previous literature; a fixed value modified by daily weather conditions; and both formulations modified by an additional coefficient to explicitly consider the vegetation water stress. The preliminary results obtained during two hydrological years (2015/2016 and 2016/2017) are compared, focusing on specific wet and dry periods.

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