Socio-economic characterization of integrated cropping systems in urban and peri-urban agriculture of Faisalabad, Pakistan

Faisalabad city is surrounded by agricultural lands, where farmers are growing vegetables, grain crops, and fodder for auto-consumption and local marketing. To study the socioeconomic impact and resource use in these urban and peri-urban agricultural production (UPA) systems, a baseline survey was conducted during 2009–2010. A total of 140 households were selected using a stratified sampling method and interviewed with a structured questionnaire. The results revealed that 96 % of the households rely on agriculture as their main occupation. Thirty percent of the households were owners of the land and the rest cultivated either rented or sharecropped land. Most of the families (70 %) were headed by a member with primary education, and only 10 % of the household head had a secondary school certificate. Irrigationwater was obtained from waste water (37 %), canals (27 %), and mixed alternative sources (36 %). A total of 35 species were cultivated in the UPA systems of which were 65% vegetables, 15% grain and fodder crops, and 5% medicinal plants. Fifty-nine percent of the households cultivated wheat, mostly for auto-consumption. The 51 % of the respondents grew cauliflower (Brassica oleracea L.) and gourds (Cucurbitaceae) in the winter and summer seasons, respectively. Group marketing was uncommon and most of the farmers sold their produce at the farm gate (45 %) and on local markets (43 %). Seeds and fertilizers were available from commission agents and dealers on a credit basis with the obligation to pay by harvested produce. A major problem reported by the UPA farmers of Faisalabad was the scarcity of high quality irrigation water, especially during the hot dry summer months, in addition to lacking adequate quantities of mineral fertilizers and other inputs during sowing time. Half of the respondents estimated their daily income to be less than 1.25 US$and spent almost half of it on food. Monthly average household income and expenses were 334 and 237 US$, respectively

Urban and peri-urban agricultural production along railway tracks: a case study from the Mumbai Metropolitan Region

Urban and peri-urban agriculture (UPA) contributes to food security, serves as an opportunity for income generation, and provides recreational services to urban citizens. With a population of 21 Million people, of which 60 % live in slums, UPA activities can play a crucial role in supporting people’s livelihoods in Mumbai Metropolitan Region (MMR). This study was conducted to characterize the railway gardens, determine their role in UPA production, and assess potential risks. It comprises a baseline survey among 38 railway gardeners across MMR characterized by different demographic, socio-economic, migratory, and labour characteristics. Soil, irrigation water, and plant samples were analyzed for nutrients, heavy metals, and microbial load. All the railway gardeners practiced agriculture as a primary source of income and cultivated seasonal vegetables such as lady’s finger (Abelmoschus esculentus L. Moench), spinach (Spinacia oleracea L.), red amaranth (Amaranthus cruentus L.), and white radish (Raphanus sativus var. longipinnatus) which were irrigated with waste water. This irrigation water was loaded with 7–28 mg N l^(−1), 0.3–7 mg P l^(−1), and 8–32 mg K l^(−1), but also contained heavy metals such as lead (0.02–0.06 mg Pb l^(−1)), cadmium (0.03–0.17 mg Cd l^(−1)), mercury (0.001–0.005 mg Hg l^(−1)), and pathogens such as Escherichia coli (1,100 most probable number per 100 ml). Levels of heavy metals exceeded the critical thresholds in surface soils (Cr, Ni, and Sr) and produce (Pb, Cd, and Sr). The railway garden production systems can substantially foster employment and reduce economic deprivation of urban poor particularly slum dwellers and migrant people. However this production system may also cause possible health risks to producers and consumers

Determinants of sustainability in urban and peri-urban agriculture

Urban and peri-urban agriculture (UPA) covers about 10% of the global food demand, and substantially contributes to the income of the urban poor. However, surprisingly little quantitative data exist about the sustainability and resource use efficiency of UPA and its contribution to maintaining plant biodiversity. Horizontal and vertical flux measurements of carbon (C), nitrogen (N), phosphorus (P) and potassium (K) as well as biodiversity studies were conducted to analyze UPA systems in selected major cities of sub-Saharan Africa. In Niamey (Niger) annual partial (horizontal) C and N balances amounted to 4,454-28,320 kg C ha-1 and -142-597 kg N ha-1 in low input gardens while in high input gardens annual surpluses of 785-19,588 kg C ha-1 and 890-2,991 kg N ha-1 were recorded. In low input river water gardens mean annual gaseous C emissions reached 20-25 t ha-1 of which 98% occurred as CO2 while NH3-N and N2O-N emissions varied from 20-29 kg ha-1 yr-1. In a high input garden irrigated with wastewater, annual CO2-C emissions amounted to 27 t ha-1 while N2O was the main contributor to measured N losses (68%) which together with NH3 reached 92 kg N ha-1 yr-1. About 28% of total annual gaseous C emissions and 30-40% of N volatilization occurred during the hot dry season from March to May and another 20-25% and 10-20%, respectively, at the onset of the rainy season in June and July. Mean annual N leaching losses ranged from 2.2-7.3 kg ha-1; annual P leaching was with 0.7 kg ha-1 negligible. Animal manure, a major source of N input in UPA systems of West Africa, but not in Khartoum (Sudan) where it is used for brick making, is typically subjected to large C and N emanation losses if stored in the open. Simple plastic sheet roofing can not only lead to substantial reductions of such losses during both the hot dry and the rainy season, particularly if combined with rockphosphate (RP) applied at 333 g kg-1 manure dry matter (DM), but also reduce nutrient losses by leaching and run off. The biodiversity studies in Niamey showed that UPA gardens can maintain a large variety of fruit and vegetable species. Plant species richness increased with garden and household size (p<0.001) and, in contrast to general belief, also with the degree of produce commercialization

Accuracy and precision of photoacoustic spectroscopy not guaranteed

Because of their accuracy and precision for measuring gas concentrations, gas chromatographs (GC) are standard analytical instruments used in investigations of nitrous oxide (N2 O) and carbon dioxide (CO2 ) exchange between the soil and the atmosphere. Iqbal et al. (2012) indicate that photoacoustic spectroscopy (PAS) performs similar to GCs for this purpose. We welcome this addition to the literature, given the increasing number of studies using PAS (e.g., Predotova et al. 2009; Leytem et al. 2011) and the few comparative analyses available (Ambus & Robertson 1998; Yamulki & Jarvis 1999). However, poor performance of PAS in some assessments (Akdeniz et al., 2009) and data from our own tests (reported below) raise questions about whether Iqbal et al.'s (2012) results are generally applicable to PAS instruments or unique to the experimental conditions and calibration of their instruments