CLIMATE CHANGE IS HAVING DRASTIC CONSEQUENCES IN CHILE. THE LACK OF WATER IN VARIOUS REGIONS IS CAUSING ENVIRONMENTAL IMPACTS ON ECOSYSTEMS, INCLUDING THE DECREASE IN THE PRODUCTIVE ACTIVITIES OF RURAL ECONOMIES AND THE DETERIORATION IN THE QUALITY OF LIFE OF THE INHABITANTS THAT OCCUPY THE AFFECTED PHYSICAL SPACES. IN THIS PAPER, WE PROPOSE A SUSTAINABLE, LOW-COST TREATMENT OF WASTEWATER AND ITS REUSE AS AN ADAPTATION AND MITIGATION POLICY, PATENTED IN 2019, THAT CONSISTS OF A WASTEWATER DISINFECTION SYSTEM BASED ON SOLAR ENERGY. THIS SYSTEM CAN WORK IN BOTH CONTINUOUS AND DISCONTINUOUS MODES. THE WATER PASSES THROUGH A CANAL OF REFLECTIVE MATERIAL IN THE CONTINUOUS REGIME, AND IN THE BATCH REGIME, THE WATER REMAINS IN THE CANAL. THE PANELS ARE LOCATED PARALLEL TO THE LATERAL FACES OF THE CANAL. THESE PANELS CONCENTRATE THE RADIATION IN THE CANAL THROUGH REFLECTION. THE TRAPEZOIDAL GEOMETRY OF THE DISINFECTANT CANAL DEFLECTS THE RADIATION AND REFLECTS IN THE DIRECTION OF THE FRONT WALLS OF THE CANAL, RADIATING WHAT IS RETURNED AND VICE VERSA. THE FRACTION OF THE RADIATION REFLECTED OUTSIDE THE CANAL REACHES THE REFLECTIVE SIDE PANELS THAT RETURN THE RADIATION TO THE CANAL. THE SYNERGY OF THESE THREE CONSIDERATIONS INCREASES THE RADIATION IN THE CANAL AREA, AUGMENTING THE ELIMINATION OF THE BACTERIAL LOAD. IN THE TRAPEZOIDAL REFLECTIVE CANAL WITHOUT PANELS, ONLY 5% OF THE MEASURED RADIATION EXCEEDED THE ATMOSPHERIC RADIATION, ELIMINATING 83% OF THE COLIFORMS. THE INCORPORATION OF PANELS SURPASSED THE ATMOSPHERIC RADIATION OVER 36% OF THE MEASURED RADIATIONS, AND THE REMOVAL OF COLIFORMS EXCEEDED 99.7%.

THE NEED ARISES TO SEEK NEW DEPURATION TECHNOLOGICAL RESPONSES AIMED AT THE REUSE OF WASTEWATER, WHICH REQUIRES THE DEVELOPMENT AND PROMOTION OF ECONOMICALLY AND ENVIRONMENTALLY SUSTAINABLE TECHNOLOGIES. IN THIS PAPER, IT STUDIES AN IMPROVEMENT TO A DISINFECTION SYSTEM SUSTAINABLE, LOW-COST, PATENTED IN 2019, AND BASED ON SOLAR ENERGY. THE WATER PASSES THROUGH A CANAL OF REFLECTIVE MATERIAL IN THE CONTINUOUS REGIME, AND IN THE BATCH REGIME, THE WATER REMAINS IN THE CANAL. THE PANELS ARE LOCATED PARALLEL TO THE LATERAL FACES OF THE CANAL. THE FRACTION OF THE RADIATION REFLECTED OUTSIDE THE CANAL REACHES THE REFLECTIVE SIDE PANELS THAT RETURN THE RADIATION TO THE CANAL. THESE PANELS CONCENTRATE THE RADIATION IN THE CANAL THROUGH REFLECTION. THE DISINFECTANT CANAL WITH FINS AND SIDE PANELS USES ULTRAVIOLET RADIATION TO ELIMINATE THE BACTERIAL LOAD CARRIED BY TREATED WASTEWATER. FOR THIS REASON, THE PRESENT WORK ANALYZES THE INCIDENCE IN THE AREA OF INFLUENCE OF THE DISINFECTANT CANAL. WHEN REFLECTIVE ALUMINUM MIRRORS WERE INSTALLED ON THE SLOPING WALLS OF THE CANAL, GLOBAL RADIATION INCREASED BY 4%, WHEN THEY WERE USED ON THE SIDE PANELS, IT INCREASED 3%, AND WHEN THE ALUMINUM MIRRORS WERE USED ON THE CANAL WALLS AND SIDE PANELS, IT INCREASED 8%. THE IMPORTANT THING ABOUT THIS WORK IS THAT IT OPENS WINDOWS FOR IMPROVING THE SYSTEM THROUGH MATERIALITY SO THE NEW CHALLENGE IS THE SEARCH FOR THE OPTIMAL MATERIAL CONSIDERING THE IMPACT ON GLOBAL RADIATION AND CONSEQUENTLY ON THE BACTERIOLOGICAL ELIMINATION.

CONTRACTUAL RELATIONSHIPS REGARDING LAND TENURE IN AGRICULTURE ARE DIVERSE. FROM FORMAL SYSTEMS SUCH AS LANDOWNER AND FIXED RENT, SHARECROPPING EMERGES AS AN ALTERNATIVE IN WHICH THE OWNER OF THE LAND SHARES THE BENEFITS AND RISKS OF THE RESULTS WITH TENANTS. THEREFORE, LAND TENURE SYSTEMS DIFFER IN TERMS OF THE INCENTIVES THAT THE LANDOWNER OFFERS TO WORKERS, WHICH CAN HAVE AN IMPACT ON PRODUCTIVITY AND PRODUCTION RISK. THE PURPOSE OF THIS WORK IS TO ANALYZE THE EFFECT OF SHARECROPPING ON THE MEAN AND VARIANCE OF TECHNICAL EFFICIENCY FOR A SAMPLE OF RICE PRODUCERS IN THE NUBLE REGION, CHILE. USING PANEL DATA OF 109 FARMERS FOR THE YEARS 2014-2015, WE ESTIMATE A STOCHASTIC FRONTIER MODEL THAT ALLOWS HETEROSKEDASTICITY IN BOTH THE GENERAL AND INEFFICIENCY-SPECIFIC ERROR COMPONENTS. THE RESULTS SHOW THAT FARMERS CULTIVATING UNDER SHARECROPPING SHOW HIGHER LEVELS OF TECHNICAL EFFICIENCY WHILE THOSE CULTIVATING LAND BY THE FIXED RENTAL SYSTEM REVEALS AN INCREASE IN THE VARIANCE OF TECHNICAL EFFICIENCY COMPARED TO LANDOWNERS. EXPLANATIONS BASED ON MORAL HAZARD PROBLEMS AND RISK-SHARING MECHANISMS ARE DISCUSSED.