Energy Inputs for Cantaloupe Production in San Joaquin Valley, California

Concerns of consumers have increased the pressure on companies to become more responsible toward the environment. Wal-mart for example is pilot studying the possibility of introducing an ‘energy’ label on their products. This paper studies the energy inputs on cantaloupe production in San Joaquin Valley (SJV), California. To estimate the energy required to produce a kilogram of cantaloupe information was collected on the operations and various inputs such as fertilizer and irrigation used by farmers in the cantaloupe capital of the world. The energy required to manufacture fertilizers and pesticides, to produce and use the farm machinery and energy consumed during irrigation was calculated using appropriate energy equivalents from the literature. The total energy input was calculated to be 910kJ kg-1 or 35.3 MJ ha-1. Fertilizer is the major energy input followed by irrigation and fuel. This number is relatively lower than estimates in the previous available data from 1980, and may be indicative of the adoption  and advancement in drip irrigation techniques used by many growers in the SJV,  and the improvement in cantaloupe cultivars better suited for the region

Adaptation of pressurized irrigation networks to new strategies ofirrigation management: Energy implications of low discharge andpulsed irrigation

This paper analyzes the consequences of adopting new on-farm irrigation management strategies (lowdischarge rates, long irrigation times and high frequencies) in an existing on-demand and sectorizedpressurized irrigation system in eastern Spain. The sectorized behavior of the network was analyzedusing two criteria: (i) the operating sectors obtained in a first stage by arranging the hydrants dependingon their altitude respecting the pumping station and (ii) the operating sectors obtained by means ofan optimization process. The Simulated Annealing combinatorial metaheuristic optimization techniquewas employed to find the best solution. Random on-demand patterns were generated using a Montecarlosimulation. The hydraulic requirements of the network were analyzed in every scenario by the Epanet2.0 engine. The effect on energy consumption, power requirements and energy costs was assessed takinginto account the electricity tariff billing structure. It was found that reductions in emitter discharge (qe)and Energy consumption (E)-Energy Cost (EC) savings are not inherently related to each other. Certainamounts of E and EC could be saved when the number of sectors and operating time parameters wereproperly selected. Pulsed irrigation in the current scenario showed an energy saving potential of 10.67,6.43 and 6.99% for power capacity, E and EC, respectively.The study has been partially funded by the IMPADAPT project (CGL2013-48424-C2-1-R) with Spanish MINECO (Ministerio de Economia y Competitividad) and Feder funds.Garcia-Prats, A.; Guillem Picó, S. (2016). Adaptation of pressurized irrigation networks to new strategies ofirrigation management: Energy implications of low discharge andpulsed irrigation. Agricultural Water Management. 169:52-60. https://doi.org/10.1016/j.agwat.2016.02.023S526016

Intermittent water application through surface and subsurface drip irrigation

Intermittent water application allows reducing mean irrigation rate to a level which coincides with soil's hydraulic conductivity and minimizes percolation below the main root zone. Field experiment was conducted to confirm the efficiency of this approach, in a clay loam soil. The treatments consisted of two irrigation systems (surface and subsurface drip), and two methods of water application (continuous and intermittent). Drip piping with 0.8-m emitter spacing was placed on the soil surface in the middle of alternative plant rows. Laterals with the same characteristics were buried at 0.45 m in the subsurface plots. The moisture distribution in the soil one day after irrigation, measured by time domain reflectometry instrumentation, indicated that intermittent application in both surface and subsurface plots produced wider wetted patterns. Intermittent or pulsed drip irrigation application has proven its potential to improve sugar beet yield. The results demonstrate that plots irrigated by intermittent application exceeded the continuous irrigated ones in terms of root yield and sugar content

Water saving with application of innovative irrigation systems and its effects on crops’ growth

The object of present research was: (i) the comparison of subsurface with surface drip irrigation in terms of water saving and water use efficiency, (ii) the development of a procedure for the calculation of crop’s evapotranspiration that takes into account the different physical characteristics of each irrigation method, (iii) the development of innovative techniques of water application through the irrigation system, (iv) the investigation of the probability of enhancing crop’s yield by the use of these techniques and (v) the investigation of the relationship between yield and climatic data and irrigation water. Field experiments were conducted in a sugar beet field of University of Thessaly Experimental Station, where surface and subsurface drip irrigation systems were installed. The experiments took place through a three-year period (2003-2005) in an experimental field with a clay loam soil. The experimental design included eight treatments in four replications. The treatments that were applied were: i) Surface drip irrigation with continuous water application, ii) Surface drip with intermittent application, iii) Surface drip with low discharge application through gravity, iv) Subsurface drip irrigation with continuous water application, v) Subsurface drip with intermittent application, vi) Subsurface drip with low discharge application through gravity, vii) Subsurface drip irrigation with continuous water application and simultaneous air application through the irrigation laterals and viii) Subsurface drip irrigation with continuous water application and air application through the irrigation laterals at the end of irrigation. The evapotranspiration (ET) and the irrigation scheduling were calculated according the methodology of FAO-56. FAO-56 does not deal with the case of subsurface drip irrigation method. In the present research the absence of wetting of the surface soil when irrigating subsurface was taken into consideration. The final result of this procedure was the important saving of irrigation water that was achieved in subsurface drip compared with surface application. The water application technique had an important effect in crop production. In all three farming periods the intermittent irrigation produced the higher fresh weight of roots. From the elaboration of water use efficiency (WUE) data resulted that subsurface intermittent irrigation is evaluated as the most efficient technique that was applied. The change of soil moisture shows that the intermittent irrigation, in both surface and subsurface systems, produced the larger wetted surfaces. The measurements of soil moisture showed that in the case of intermittent irrigation the uniformity of soil moisture was higher compared to that of continuous application. The wetting front measurements revealed that the horizontal development of the wetting front was increased in the case of intermittent irrigation, in both irrigation methods. The development of wetted diameter with time in the surface intermittent irrigation, is described with a linear equation, instead of the exponential one that is used in the conventional drip.Αντικείμενο της παρούσας εργασίας ήταν: (i) η σύγκριση της υπόγειας µε την επιφανειακή στάγδην άρδευση µε όρους εξοικονόμησης και αποδοτικότητας χρήσης νερού, (ii) η ανάπτυξη μιας διαδικασίας υπολογισμού της εξατµισοδιαπνοής της καλλιέργειας που λαμβάνει υπόψη τα διαφορετικά φυσικά χαρακτηριστικά κάθε μεθόδου άρδευσης, (iii) η ανάπτυξη καινοτόμων τεχνικών εφαρμογής του νερού από το σύστημα άρδευσης, (iv) η διερεύνηση της πιθανότητας βελτίωσης της απόδοσης της καλλιέργειας µε τη χρήση αυτών των τεχνικών και (v) η διερεύνηση της σχέσης μεταξύ της παραγωγικότητας της καλλιέργειας και κλιματικών δεδομένων και αρδευτικού νερού. Έγιναν πειράματα ζαχαροτεύτλων σε αγρό του Αγροκτήματος του Πανεπιστημίου Θεσσαλίας, όπου εγκαταστάθηκαν συστήματα υπόγειας και επιφανειακής στάγδην άρδευσης. Τα πειράματα πραγματοποιήθηκαν την τριετία 2003-2005 σε πειραµατικό αγρό µε έδαφος αργιλοπηλώδες. Το πειραµατικό σχέδιο περιελάμβανε οχτώ μεταχειρίσεις σε τέσσερις επαναλήψεις. Οι μεταχειρίσεις που εφαρμόσθηκαν ήταν: i) Επιφανειακή εφαρµογή νερού µε σταγόνα, ii) Επιφανειακή διακοπτόμενη εφαρµογή µε σταγόνα, iii) Επιφανειακή εφαρµογή χαμηλής παροχής µε σταγόνα δια της βαρύτητας, iv) Υπόγεια εφαρµογή νερού µε σταγόνα, v) Υπόγεια διακοπτόμενη εφαρµογή µε σταγόνα, vi) Υπόγεια εφαρµογή χαμηλής παροχής µε σταγόνα δια της βαρύτητας, vii) Υπόγεια εφαρµογή νερού µε σταγόνα µε ταυτόχρονη εφαρµογή αέρα και viii) Υπόγεια εφαρμογή νερού µε σταγόνα µε εφαρμογή αέρα στο τέλος της άρδευσης. Ο υπολογισμός της εξατµισοδιαπνοής (ΕΤ) και ο προγραμματισμός των αρδεύσεων ακολούθησαν την μεθοδολογία FAO-56. Η μεθοδολογία FAO-56 δεν πραγματεύεται την περίπτωση της μεθόδου άρδευσης µε υπόγεια σταγόνα. Στην παρούσα έρευνα λήφθηκε υπόψη η µη διαβροχή του επιφανειακού εδάφους. Ως τελικό αποτέλεσμα αυτής της διαδικασίας, ήταν η σημαντική εξοικονόμηση αρδευτικού νερού που επιτεύχθηκε στην υπόγεια στάγδην σε σχέση µε την επιφανειακή. Η τεχνική εφαρμογής του νερού είχε σημαντική επίδραση στην παραγωγή. Και στις τρεις καλλιεργητικές περιόδους η διακοπτόμενη άρδευση έδωσε το υψηλότερο νωπό βάρος ριζών. Από την αξιολόγηση της αποδοτικότητας χρήσης νερού προέκυψε ότι η υπόγεια διακοπτόμενη άρδευση αξιολογείται ως η πλέον αποδοτική τεχνική που εφαρμόσθηκε, αφού παρουσίασε τις υψηλότερες τιμές τόσο σε αποδοτικότητα νερού άρδευσης όσο και σε συνολική αποδοτικότητα και για τα τρία έτη πειραματισμού. Η μεταβολή της εδαφικής υγρασίας δείχνει πως η διακοπτόμενη άρδευση, τόσο στο επιφανειακό όσο και στο υπόγειο σύστημα, παρήγαγε μεγαλύτερες επιφάνειες διαβροχής. Η καταγραφή της υγρασίας στην εδαφική κατατομή έδειξε πως στις εφαρμογές διακοπτόμενης άρδευσης η ομοιομορφία της υγρασίας ήταν καλύτερη σε σχέση µε αυτήν της συνεχούς εφαρμογής. Γενική διαπίστωση αποτελεί η αυξημένη οριζόντια ανάπτυξη του υγρού μετώπου στην περίπτωση της διακοπτόμενης άρδευσης, τόσο στο υπόγειο σύστημα όσο και στο επιφανειακό. Στην περίπτωση άρδευσης µε χαμηλή παροχή η καθοδική κίνηση του νερού είναι μεγαλύτερη και η οριζόντια μικρότερη από τις άλλες μεταχειρίσεις. Η ανάπτυξη της διαβροχής µε το χρόνο στην επιφανειακή διακοπτόμενη άρδευση, περιγράφεται µε μια γραμμική εξίσωση εν αντιθέσει µε την εκθετική που χρησιμοποιείται για την περιγραφή της στη συμβατική στάγδην άρδευση

Aerogation: Crop root-zone aeration through subsurface drip irrigation system

Subsurface drip irrigation as a source that provides the water directly to the root zone develops a saturated wetted front in the rhizosphere, particularly when the irrigation is close to 100% of evapotranspiration. Long duration irrigations collect root development around the drip emitters and relatively low hydraulic conductivity, mainly in heavy soils, lead to preservation of saturation in the root layer, resulting in lack of air, which is detrimental to the function of roots and directly influences crop development. The objective of this study is to examine whether the root zone aeration can improve the distribution of moisture in the soil thereby improving plant performance. For the investigation of this approach, a three-year experimental research was conducted, in a sugar beet crop, irrigated by a subsurface drip irrigation system. A technique for ventilating the root zone was developed, which comprises passing air in the irrigation water throughout the duration of irrigation using a venturi device and air supply under pressure after irrigation through a compressor. The air application (aerogation) affected the soil moisture in the root zone reducing the water content or repelled the water from the proximal environment of the emitter. Regarding the crop yield characteristics, the continuous air application gave a higher yield, although not statistically significant, than the conventional (without air) irrigation and aeration at the end of irrigation

ScienceDirect Agricultural use of microfiltered olive mill wastewater: effects on maize production and soil properties

Abstract The disposal of olive mill wastewater (OMWW) is considered as one of the most serious environmental problems in the Mediterranean region. This study constitutes part of a holistic OMWW management approach aiming at the production of high added value products from OMWW with zero discharge. OMWW constitutes an organic material that could be recycled back to the soil after its treatment with microfiltration, and used as liquid fertilizer for plant production, thus leading to an environmentally friendly cultivation method with minor carbon footprint, since wastewater would (partially or fully) substitute mineral fertilizers, fresh water savings, and also economic benefits to the farmer. Microfiltered OMWW (MF-OMWW) was applied to maize cultivation in a clay loam soil using two rates of 25 and 50 Mg ha -1 , with the addition of mineral fertilization of 200 kg N ha -1 . Furthermore, a treatment of only MF-OMWW applied at the rates of 50 Mg ha -1 and an only mineral fertilization treatment were used. The four treatments were replicated four times. The results of the 1 st year experiment showed that the different amounts of MF-OMWW used had no significant effect on soil properties. Maize yield, kernel moisture and fat content were not significantly influenced by the different treatments, whereas kernel protein, starch, fiber and ash content were significantly affected. Considering all quality and quantity parameters studied, the treatment with only mineral fertilizer N application gave similar results with the only MF-OMWW treatment, indicating the potential of mineral fertilizer full substitution by MF-OMWW, under the conditions of our study

Maize Fertigation with Treated Olive Mill Wastewater: Effects on Crop Production and Soil Properties

The present study investigates the potential of olive mill wastewater, treated by microfiltration and XAD4 macroporous resin, to be used as liquid fertilizer in maize production through a 2-year field experiment. The treated olive mill wastewater (T-OMWW) was applied at two rates of 25 t and 50 t per ha per year, supplemented with mineral fertilization. There was also a treatment involving the application of only T-OMWW at the rate of 50 t per ha per year, and an only mineral fertilizer treatment. Mineral fertilizers and T-OMWW were applied progressively through a drip irrigation system. Maize grain and soil analysis showed that T-OMWW was capable to meet crop requirements in N, P and K, and increase soil N, P and K availability. There was a tendency for increasing soil Na and electrical conductivity (EC) using the higher rate of T-OMWW. Therefore, for sustainable agriculture, it may be safer to apply the T-OMWW at the lower rate of 25 t per haper year, or use the higher rate of 50 t per haevery other year