Irrigation Of Vegetables Research Articles

Water Loss Due to Increasing Planted Vegetation over the Badain Jaran Desert, China

Water resources play a vital role in ecosystem stability, human survival, and social development in drylands. Human activities, such as afforestation and irrigation, have had a large impact on the water cycle and vegetation in drylands over recent years. The Badain Jaran Desert (BJD) is one of the driest regions in China with increasing human activities, yet the connection between human management and the ecohydrology of this area remains largely unclear. In this study, we firstly investigated the ecohydrological dynamics and their relationship across different spatial scales over the BJD, using multi-source observational data from 2001 to 2014, including: total water storage anomaly (TWSA) from Gravity Recovery and Climate Experiment (GRACE), normalized difference vegetation index (NDVI) from Moderate Resolution Imaging Spectroradiometer (MODIS), lake extent from Landsat, and precipitation from in situ meteorological stations. We further studied the response of the local hydrological conditions to large scale vegetation and climatic dynamics, also conducting a change analysis of water levels over four selected lakes within the BJD region from 2011. To normalize the effect of inter-annual variations of precipitation on vegetation, we also employed a relationship between annual average NDVI and annual precipitation, or modified rain-use efficiency, termed the RUEmo. A focus of this study is to understand the impact of the increasing planted vegetation on local ecohydrological systems over the BJD region. Results showed that vegetation increases were largely found to be confined to the areas intensely influenced by human activities, such as croplands and urban areas. With precipitation patterns remaining stable during the study period, there was a significant increasing trend in vegetation greenness per unit of rainfall, or RUEmo over the BJD, while at the same time, total water storage as measured by satellites has been continually decreasing since 2003. This suggested that the increased trend in vegetation and apparent increase in RUEmo can be attributed to the extraction of ground water for human-planted irrigated vegetation. In the hinterland of the BJD, we identified human-planted vegetation around the lakes using MODIS observations and field investigations. Four lake basins were chosen to validate the relationship between lake levels and planted vegetation. Our results indicated that increasing human-planted vegetation significantly increased the water loss over the BJD region. This study highlights the value of combining observational data from space-borne sensors and ground instruments to monitor the ecohydrological dynamics and the impact of human activities on water resources and ecosystems over the drylands.

Tools for monitoring aquatic environments to identify anthropic effects.

Anthropic activities are directly related to the contamination of aquatic ecosystems owing to the release of numerous chemicals from agricultural and urban waste. These contaminants cause environmental degradation and a decrease in the availability of water quality. The objective of this search was to evaluate the efficiency of physicochemical, chemical, and microbiological tests; extraction of chlorophyll a; and genetic parameters to identify anthropic activities and weather condition effects on the stream water quality and the consequences of its use by the population. The physicochemical parameters were within the limits allowed by the Brazilian law. However, contamination by metals (Cd 0.510mgL-1, Co 0.405mgL-1, and Ni 0.316mgL-1) has been found at various collection points to be more than the allowable values. The antibiotic oxytetracycline was detected in stream water in quantities of up to 89μgL-1. In relation to microbiological contamination, Escherichia coli and Pseudomonas spp. have been isolated. The averages of chlorophyll a were up to 0.15558mgcm-2. Genetic tools identified greater number of micronuclei and DNA damage in periods that showed lower rainfall rates and lower amounts of metals. The analysis used for monitoring was efficient to verify the interference that animal breeding and planting of different cultures have caused on that stream. Thus, the continued use of this water for drinking, irrigation of vegetables, and recreational activities makes the population susceptible to contamination by bacteria and creates conditions for the development of genetic alterations in the long run.

Parasites of importance for human health on edible fruits and vegetables in Nigeria: a systematic review and meta-analysis of published data

Contamination of edible fruits and vegetables is now a global public health issue despite their health benefits as non-pharmacological prophylaxis against chronic diseases. Studies that will harness the extent of parasitic contaminations will ensure public health protection. Here, the prevalence and distribution of parasites of importance for human health on fruits and vegetables in Nigeria were determined through a systematic review and meta-analysis of published data. The random-effects model was used to determine pooled prevalence estimate (PPE). Heterogeneity was evaluated by the Cochran’s Q-test. Parasites overall PPE of 32.4% (95% CI: 0.73, 0.91) was observed from 19 eligible studies reported across 13 Nigerian states. Sub-groups PPEs ranged between 3.5% (95% CI: 0.45, 1.86) and 58.5% (95% CI: 1.40, 4.09). A high degree of heterogeneity 97.53% (95% CI: 0.30, 0.46, P: 0.000) was observed within studies and sub-groups. Cryptosporidium species were the most prevalent, while Ancylostoma duodenale and Ascaris lumbricoides had the widest geographical distribution. Pineapple (Prev: 41.3%, 95% CI: 0.40, 0.75) and lettuce (Prev: 51.5%, 95% CI: 0.37, 0.68) recorded the highest level of parasitic contamination. Parasites of importance for human health are prevalent on edible fruits and vegetables in Nigeria. Prevalence estimates were highest in the South-eastern region and during the most recent decade. Adequate washing of fruits and vegetables, on-farm irrigation of vegetables using good sources of water and adequate hygiene by food handlers will help the general public to maximize the health benefits associated with the intake of fruits and vegetables while minimizing the risk of acquiring parasitic infections.

Pre harvest and post-harvest assessment of geohelminth and protozoan parasites contamination of vegetables in Ibadan, Southwest, Nigeria.

Consumption of fresh vegetables is one of the major routes of transmission of intestinal parasites of public health importance which have been incriminated as one of the main causes of foodborne outbreaks. In an attempt to bridge the knowledge gap associated with the pre-harvest and post-harvest parasitic contamination of vegetables in Nigeria, this study was conducted to assess geohelminths and protozoa contamination of vegetables in farms and markets in Ibadan, southwest, Nigeria. Vegetable samples were screened using simple floatation and sedimentation methods for identification of geohelminths ova, larva and protozoan oocysts. Of the total 200 vegetable samples collected, 70 (35%) were positive for geohelminth and protozoan parasites. The results show that the highest level of contamination was detected in African spinach 20 (35.1%), followed by White jute 15 (45.5%), Waterleaf 14 (51.9%), Quill grass 12 (24.5%), Garden eggplant leaf 4 (57.1%), while the least number of contaminated samples was detected in Pepper 1 (%). However, Fluted pumpkin leaves and English Spinach had no parasitic contamination. Waterleaf 3 (11.11%), African spinach 2 (3.5%), Quill grass 2 (4.1%) and White jute 2 (6.1%) had mixed helminths and protozoa infections. Of the total intestinal parasites observed, Strongyloides stercoralis had the highest prevalence 67 (33.5%), followed by Entamoeba coli 27 (13.5%), Ascaris spp. 24 (12%), Trichuris spp. 10 (5%), Filiariform 9 (4.5%), Dicrocoelium spp. 9 (4.5%), Oesophagostomum dentatum 7 (3.5%), Fasciola spp 7 (3.5%), Entamoeba histolytica 6 (3%) while Eimeria spp 6 (3%) had the lowest prevalence. Most farmers 44 (80%) used stream and waste water as their source of irrigation while 11 (20%) of the farmers used well and stream. The relatively high rate of parasitic contamination observed in this study might be due to poor hygienic and sanitary handling of vegetables, poor transportation, packaging of vegetables and contaminated water used for irrigation and washing of vegetables in farms and markets. There is therefore a need for education of farmers and market women on proper handling and hygienic management of vegetables to safe guard the health of the populace.

Small-scale risk assessment of transmission of parasites from wastewater treatment plant to downstream vegetable farms.

The aim of the present study was to simultaneously investigate parasitic contamination of treated wastewater and downstream vegetable farms that are irrigated with treated sewage, during a year. (Oo) Cysts and eggs of parasites are resistant to most of routine wastewater treatment process. Irrigation of vegetables farms with either treated wastewater or illegally use of raw wastewaters enhances the risk of contamination with enteric pathogens. The treated wastewater samples were taken after chlorination from a wastewater treatment plant located at the south of Tehran. In addition, 60 vegetable samples (5 samples from each farm) were collected from the selected downstream farms that routinely used treated wastewater for irrigation of crops. Parasitological tests were performed using Ziehl-Neelsen, conventional lugol's iodine staining and direct microscopical examination. Parasites including free living larvae, eggs of Toxoascaris leonina, egg of Toxocara sp. Trichuris sp, Trichostrongylus sp and amoeboid trophozoite were seen in 5/12 (41.7%) of vegetable samples gathered during a year. There was no statistically significant correlation between the season and parasitic contamination of the vegetables (P= 1). Furthermore, parasitic contamination was observed in 7/12 (53.8%) of treated wastewater samples. The correlation between season and parasitic contamination of treated wastewater was evaluated that the results showed a higher contamination of treated wastewater in spring and autumn (P<0.05). Fisher's exact test also showed that there was no significant correlation between parasitic contaminations of vegetable samples and treated wastewater according to seasonal change. The results showed parasites in both treated wastewater plant and downstream crops farms that suggests the public health importance of the quality of water resources that routinely used for irrigation of vegetable farms.

Microbial and Heavy Metal Analysis of Irrigation Water and Vegetables Grown and Consumed in Abakaliki Metropolis

Microbial and Heavy Metal Analysis of Irrigation Water and Vegetables Grown and Consumed in Abakaliki Metropolis

Design and Modeling of an Adaptively Controlled Rainwater Harvesting System

Management of urban stormwater to mitigate Combined Sewer Overflows (CSOs) is a priority for many cities; yet, few truly innovative approaches have been proposed to address the problem. Recent advances in information technology are now, however, providing cost-effective opportunities to achieve better performance of conventional stormwater infrastructure through a Continuous Monitoring and Adaptive Control (CMAC) approach. The primary objective of this study was to demonstrate that a CMAC approach can be applied to a conventional rainwater harvesting system in New York City to improve performance by minimizing discharge to the combined sewer during rainfall events, reducing water use for irrigation of local vegetation, and optimizing vegetation health. To achieve this objective, a hydrologic and hydraulic model was developed for a planned and designed rainwater harvesting system to explore multiple potential scenarios prior to the system’s actual construction. Model results indicate that the CMAC rainwater harvesting system is expected to provide significant performance improvements over conventional rainwater harvesting systems. The CMAC system is expected to capture and retain 76.6% of roof runoff per year on average, as compared to just 14.8% and 41.3% for conventional moisture and timer based systems, respectively. Similarly, the CMAC system is expected to use 81.4% and 18.0% less harvested rainwater than conventional moisture and timer based irrigation approaches, respectively. The flexibility of the CMAC approach to meet competing objectives is promising for widespread implementation in New York City and other heavily urbanized areas challenged by stormwater management issues.

Modelling the impact of future socio-economic and climate change scenarios on river microbial water quality.

Microbial surface water quality is important, as it is related to health risk when the population is exposed through drinking, recreation or consumption of irrigated vegetables. The microbial surface water quality is expected to change with socio-economic development and climate change. This study explores the combined impacts of future socio-economic and climate change scenarios on microbial water quality using a coupled hydrodynamic and water quality model (MIKE21FM-ECOLab). The model was applied to simulate the baseline (2014-2015) and future (2040s and 2090s) faecal indicator bacteria (FIB: E. coli and enterococci) concentrations in the Betna river in Bangladesh. The scenarios comprise changes in socio-economic variables (e.g. population, urbanization, land use, sanitation and sewage treatment) and climate variables (temperature, precipitation and sea-level rise). Scenarios have been developed building on the most recent Shared Socio-economic Pathways: SSP1 and SSP3 and Representative Concentration Pathways: RCP4.5 and RCP8.5 in a matrix. An uncontrolled future results in a deterioration of the microbial water quality (+75% by the 2090s) due to socio-economic changes, such as higher population growth, and changes in rainfall patterns. However, microbial water quality improves under a sustainable scenario with improved sewage treatment (-98% by the 2090s). Contaminant loads were more influenced by changes in socio-economic factors than by climatic change. To our knowledge, this is the first study that combines climate change and socio-economic development scenarios to simulate the future microbial water quality of a river. This approach can also be used to assess future consequences for health risks.

Evaluating the Effectiveness of Mitigation Options on Heat Stress for Sydney, Australia

AbstractGlobal warming, in combination with the urban heat island effect, is increasing the temperature in cities. These changes increase the risk of heat stress for millions of city dwellers. Given the large populations at risk, a variety of mitigation strategies have been proposed to cool cities—including strategies that aim to reduce the ambient air temperature. This paper uses common heat stress metrics to evaluate the performance of several urban heat island mitigation strategies. The authors found that cooling via reducing net radiation or increasing irrigated vegetation in parks or on green roofs did reduce ambient air temperature. However, a lower air temperature did not necessarily lead to less heat stress because both temperature and humidity are important factors in determining human thermal comfort. Specifically, cooling the surface via evaporation through the use of irrigation increased humidity—consequently, the net impact on human comfort of any cooling was negligible. This result suggests that urban cooling strategies must aim to reduce ambient air temperatures without increasing humidity, for example via the deployment of solar panels over roofs or via cool roofs utilizing high albedos, in order to combat human heat stress in the urban environment.

Performance and water usage of selected vegetables grown with different irrigation systems under house-type structures

Irrigation for vegetables grown under protected cropping is very important for optimum production. Likewise, choosing an efficient method of irrigation can save water and labour. These studies were conducted to evaluate the effects of manual sprinkler, drip bottle, and drip hose method of water delivery systems on performance of selected vegetables, water use efficiency and profitability grown in house-type protective structures. The three crops tested were tomato, sweet pepper and ampalaya which were planted in similar structures arranged in randomized complete block design with three replications. The drip bottle method increased yield, irrigation water use efficiency, and profitability compared to sprinkler and drip hose method. Drip hose method effectively suppressed fusarium wilt. This implies that increasing productivity of some vegetables requires water delivery systems that provide a constant and even supply using a small amount of water. Further work is required in scheduling and rate of application with the drip hose method for it to become as efficient as the drip bottle.

Биопродуктивность овса на мерзлотной лугово-черноземной почве Центральной Якутии

Овес в районах широкого распространения многолетнемерзлых пород, где развито земледелие, является ведущей кормовой культурой. В статье представлены результаты исследования по продуктивности овса, по влиянию вегетационных поливов на урожайность зеленой массы, содержание питательных веществ, сбор кормовых единиц, сырого протеина, обменной энергии на мерзлотной лугово-черноземной суглинистой почве в условиях Центральной Якутии при сухой и жаркой погоде в период вегетации сельскохозяйственных культур. Объектом исследований служил овес сорта Покровский 9. Схема опыта включала вариант без полива (контроль), полив по основным фазам вегетации в норме 300 м3/га. Выявлено, что орошение по основным фазам развития растений способствовало увеличению урожайности зеленой массы овса до 12,2 т/га. При орошении, особенно на ранних фазах развития растений, наблюдалось более ускоренное накопление углеводов и белковых соединений. В варианте полива в растениях заметно повышалось содержание сырого жира — до 11,47 – 14,54 %, сырой клетчатки в фазах «выметывание-цветение» и «цветение — молочная спелость» — до 43,35 – 35,31 %. В растениях в 1 кг сухого вещества наблюдалось снижение содержания калия — до 18,44 – 18,94 % и БЭВ — до 41,5 – 42,8 %. Отмечена тенденция к повышению содержания в растениях фосфора — до 0,26 – 0,28 % и калия — до 1,40 – 1,63 % при поливе, что положительно влияло на качество корма. При вегетационных поливах, проводимых в критические фазы развития растений, биопродуктивность овса увеличивалась на 30 – 35 %, а питательность овса повышалась на 20 – 30 %.

Peri-Urbanism in Globalizing India: A Study of Pollution, Health and Community Awareness.

This paper examines the intersection between environmental pollution and people’s acknowledgements of, and responses to, health issues in Karhera, a former agricultural village situated between the rapidly expanding cities of New Delhi (India’s capital) and Ghaziabad (an industrial district in Uttar Pradesh). A relational place-based view is integrated with an interpretive approach, highlighting the significance of place, people’s emic experiences, and the creation of meaning through social interactions. Research included surveying 1788 households, in-depth interviews, participatory mapping exercises, and a review of media articles on environment, pollution, and health. Karhera experiences both domestic pollution, through the use of domestic waste water, or gandapani, for vegetable irrigation, and industrial pollution through factories’ emissions into both the air and water. The paper shows that there is no uniform articulation of any environment/health threats associated with gandapani. Some people take preventative actions to avoid exposure while others do not acknowledge health implications. By contrast, industrial pollution is widely noted and frequently commented upon, but little collective action addresses this. The paper explores how the characteristics of Karhera, its heterogeneous population, diverse forms of environmental pollution, and broader governance processes, limit the potential for citizen action against pollution.

Production of new early ripening hybrids of large fruited pumpkin (Cucurbita maxima) based on functional male sterility

Breeders of the All-Russia Research Institute of Irrigated Vegetable and Melon Growing created new breeding valuable maternal lines CL fms (cut-leaved, choriphyllous) and EL fms (entire-leaved, integrifolious) with the functional male sterility and high general combining ability suitable for the production of early ripening F1 hybrids of large fruited pumpkin. The conducted analysis of pollen of the forced open anthers of flowers with the functional male sterility demonstrated its high fertility (90.2%) allowing the use of this pollen for artificial pollination. It was found that the functional male sterility of large fruited pumpkin is inherited recessively and controlled by the one gene. Maternal lines CL fms and EL fms demonstrated a high level of general combining ability for the “ripeness” trait. F1 hybrids obtained based on these lines were superior to the standard mid-early ripening pumpkin variety Kroshka at 10–18 days; isolated hybrid combinations were at the level of standard variety in terms of yield and solids content. Maternal lines CL fms and EL fms allow the production of the hybrid offspring with brightly colored fruits in contrast to the maternal line LF fms (large fruited) that provided the hybrids with fruits that had different shades of gray color of the cortex. The majority of hybrid combinations allow obtaining fruits of portion size with an average weight of 1–3 kg and high productivity. F1 hybrid combination EL fms × Konfetka-ultra early ripening with colored fruits of portion size and high biochemical indexes was distinguished based on the complex of agronomic characters.

Health Risks Assessment Diagnosis of Toxic Chemicals (Heavy Metals) via Food Crops Consumption Irrigated with Wastewater

The present study investigated the concentration of metals in commonly grown vegetables (Luffa acutangula L., Zea mays L., Solanum melongena L.) irrigated with waste water in District Bannu, Khyber Pakhtunkhwa, Pakistan. The pH (5.80) and electrical conductivity (13 dS/m) of waste water indicated the acidic nature that is not suitable for irrigation purposes. Soil and vegetables samples were analyzed for metals concentration through flame atomic absorption spectrometry (Varian FAAS-240). The findings showed that waste water irrigated soil was highly contaminated with Cd (4.62 mg/kg) which was above permissible limits set by European Union Standard (EU 2006, 2002). The concentrations of heavy metals such as Cr and Cd in vegetables were higher than the permissible limits set by World Health Organization/Food and Agriculture Organization U.S.A guidelines 2001. The health hazard quotient (HQ) of waste water irrigated vegetables was observed higher for Ni (0.699-0.1029 mg/kg), (0.0456-0.1040 mg/kg), (0.731-0.0994 mg/kg) in Luffa acutangula, Solanum melongena and Zea mays, respectively. The study concluded that the consumption of commonly grown vegetables in waste water zone of the study area may pose potential health threats in local population.

Characterization of antibiotic resistant and pathogenic Escherichia coli in irrigation water and vegetables in household farms

This study aimed to characterize Escherichia coli present in irrigation water and vegetables from 16 household farms. Isolates were obtained from 50% of water (n=210 isolates) and 38% of vegetable samples (n=239). Phylogroups B1 (56% of isolates) and A (22%) were the most prevalent both in water and vegetables. Diarrheagenic strains were detected in vegetables. Irrespective of the source (i.e. water or vegetables), the most common antibiotic resistance was against streptomycin (89% resistant isolates) and tetracycline (24%). Common acquired genes (e.g. blaTEM, tetA, tetB) were found in isolates from both sources. Class I integrons were detected in water (arrays dfrA1-aadA1 and dfr16-blaP1b-aadA2-ereA) and vegetables (unknown arrays). intI2 was detected in water (dfrA1-sat2-aadA1). Plasmids were detected in 14 isolates (IncFIC, IncFIB, IncFrep, IncI1 in both samples; IncY in vegetables). Plasmids from seven isolates were transferrable by conjugation, conferring resistance to antibiotics to the recipient strain. Multidrug-resistant (MDR) strains were isolated from water (12% of the unique isolates) and vegetables (21%). Predominant sequence types (STs) among MDR isolates were ST10, ST297 and ST2522. In some cases, the same STs and identical clones (as showed by rep-PCR typing) were detected in water and vegetables, suggesting cross-contamination. This study identified several risk factors in E. coli isolates from vegetables and irrigation water, raising health concerns. Also, results suggest that irrigation groundwater constitutes a source of E. coli that may enter the food chain through vegetables ingestion.

New Trends in the Fertigation Management of Irrigated Vegetable Crops

The use of fertigation, coupled with micro-irrigation, has continued to increase since it was first introduced in horticultural cropping systems. This combination provides a technical solution whereby nutrients and water can be supplied to the crop with high precision in terms of time and space, thereby allowing high nutrient use efficiency. However, the correct estimation of crop nutrient and water needs is fundamental to obtaining precise plant nutrition and high nutrient use efficiency in fertigated cropping systems. This paper illustrates the state-of-the-art and new perspectives for optimal nutrient management of vegetable crops cultivated under fertigation regimes. An overall description is reported for the most valuable technologies and techniques based on simulation models, soil testing, plant testing, and related decision support systems that can be adopted for efficient fertigation. However, it should be highlighted that only a few of the above technologies and techniques are practically available and/or easy to use by growers. Therefore, much more attention should be paid in the future to the transfer of research knowledge to farmers and technical advisors.

Study on the efficiency of continuous flow-based constructed wetland system for grey water treatment

Water is inevitable for our life. Due to the population growth, there is a tremendous pressure on the existing fresh water resources such as surface water and ground water. Increasing water demand and improper usage of potable water lead to scarcity of fresh water resources. Globally, treating grey water is a real constraint to minimize the problem of water scarcity. The continuous flow-based constructed wetland system for grey water treatment is a technique for reusing the domestic grey water and it is a low-cost method. The current study was aimed to evolve a suitable user-friendly treatment system for handling the household grey water. In the present study, grey water has been collected from the Bharathidasan University and it has been treated with biofiltration and rhizhodegradation techniques using continuous flow-based constructed wetland system. The system has been found as more effective for treating the Physico-chemical parameters such as suspended solids, pH, electrical conductivity, TS, TDS, DO, BOD, COD, TOC, CO3, HCO3, SO4, NO3, PO4, Ca, Mg, Na, K, total hardness, calcium hardness, chloride, and total alkalinity. The results reported the reduction in the biological oxygen demand (89%), chemical oxygen demand (81%), DO (95%), carbonate (100%), sodium (65%), and potassium (85%).It also examined the benefits and risks associated with the results in the reuse of domestic grey water for the purpose of vegetable gardening, irrigation, and toilet flushing. Consequently, this biofiltration method is natural, simple, and low cost-effective treatment in a holistic manner.

Water for Agriculture: the Convergence of Sustainability and Safety.

Agricultural water is a precious and limited resource. Increasingly more water types and sources are being explored for use in irrigation within the United States and across the globe. As outlined in this chapter, the Produce Safety Rule (PSR) in the Food Safety and Modernization Act (FSMA) provide irrigation water standards for application of water to fruits and vegetables consumed raw. These rules for production and use of water will continue to develop and be required as the world experiences aspects of a changing climate including flooding as well as drought conditions. Research continues to assess the use of agricultural water types. The increased use of reclaimed water in the United States as well as for selected irrigation water needs for specific crops may provide increased water availability. The use of surface water can be used in irrigation as well, but several studies have shown the presence of some enteric bacterial pathogens (enterohemorrhagic E. coli, Salmonella spp. and Listeria monocytogenes) in these waters that may contaminate fruits and vegetables. There have been outbreaks of foodborne illness in the U.S., South America, Europe, and Australia related to the use of contaminated water in fruit and vegetable irrigation or washing. Unreliable water supplies, more stringent microbial water standards, mitigation technologies and expanded uses of reclaimed waters have all increased interest in agricultural water.

Technical efficiency of irrigated vegetable production among smallholder farmers in the Guinea Savannah, Nigeria

This study was carried out to analyse the technical efficiency of irrigated vegetable production among smallholder farmers in the guinea savannah, Nigeria, and determine the cost and returns on irrigated vegetable production. Two-stage sampling technique was used, purposive selection of two states and three Local Government areas each from the two states where irrigated vegetable was predominant; and random selection of twenty irrigated vegetable farmers each from the three selected areas. A total of 120 farmers were interviewed with well-structured questionnaires. Data collected were subjected to analysis using descriptive statistics, stochastic frontier model, gross margin and net farm income. The study revealed that farm size, labour and fertilizer positively affect the technical efficiency of the farmers. The mean technical efficiency was 68.5 and vegetable farmers were not operating at the optimal level of technical efficiency. The net farm income per hectare of irrigated vegetable was estimated to be ₦58,222/ha which represent88% profit on the invested capital. It is therefore concluded that irrigated vegetable farming was profitable and farmers have opportunity to improve on their technical efficiency in the area.Keywords: Technical efficiency, Irrigated vegetable, Guinea savannah, Nigeria

Incremento de la materia orgánica del suelo y rendimiento de mango en Luvisoles, Campeche, México

The objective of this study was to determinate the effect of increasing soil organic matter on fruit yield of mango trees under irrigated conditions, in Luvisols of Campeche State, Mexico. In every 48 commercial orchards and five sites under natural forest vegetation, soil samples were taken in order to determine physical and chemical properties. Furthermore, in orchards sites, leaf sampling was carried out, and data on orchard management practices and fruit yield also were registered. The collected data was analyzed using regression analysis. From soil organic matter content in continues sole maize cropping system under rainfed agriculture or irrigated vegetables, soil organic matter content in mango orchards increased from 3.26% in a period since 1 to 5 years to 5.66% after a period of 16 to 30 years. In soil under natural forest vegetation, organic matter content was 5.36%. Increasing soil organic matter content and tree age, fruit yield increased by 9.5 t/ha after 26 to 30 years under cultivation.