The sustainability of a farm system greatly relies on fertilizers and other inputs. Soil factors such as texture and local rainfall, along with management-related factors such as soil organic matter, aggregate stability and agronomic practices, have much greater influence on the sustainability of any given farm than do the type or amount of soil amendments. Growers use a wide variety of practices to maintain or improve soil health in organic vegetable production systems. These practices generally are part of long-term, site-specific management programs that aim at developing fertile and biologically active soils that readily capture and store water and nutrients, have good tilth, and suppress plant diseases. Field experiments were conducted in 2005 and 2006 in Mashhad, Iran, to study the effects of organic amendments, synthetic fertilizers and compost extracts on crop health, productivity and storability of tomato (Lycopersicon esculentum Mill.). Treatments included different fertilizers of cattle, sheep and poultry manures, green-waste and household composts and chemical fertilizers of urea and superphosphate; and five aqueous extracts from cattle manure, poultry manures, green-waste, and household composts plus water as control. Our results show that application of poultry manure showed lower disease incidence, as shown by 80% healthy tomato, compared with the other fertilizers. However, the organic fertilizers used did not give higher yields compared with chemical fertilizers. Sheep manure and chemical fertilizers led to the highest total tomato yield. Marketable yield was highest in poultry manures, of 16 t/ha, and lowest in chemical fertilizer, of 7 t/ha, 6 weeks after storage. The effect of aqueous extracts was not significant on either crop health or tomato yield and the results were inconsistent. The compost made of poultry manure therefore appears to be a promising ecological alternative to classical fertilizers. compost / crop health / lycopersicum esculentum / manure / marketable yield

No abstract

No abstract

The effects of chemical and organic fertilizers on saffron (Crocus sativus) were studied in a field experiment using a complete randomized block design with three replications at ferdowsi university of Mashhad. Fertilizers applied were N, P, K, NP, NK, PK, NPK, cow, sheep and chicken manure. The amount of chemical fertilizer applied were 50, 30, 30, 48, 48, 36, 66 kg/ha for N, P, K, NP, NK, PK, NPK and 12, 8, 4 t/ha for cow, sheep and chicken manures, respectively. The results indicated that number and weight of flower and stigma dry weight were affected by type of fertilizers (p<0.01). The highest flower number was obtained with cow manure and the lowest with N, NK and PK fertilizers. The highest stigma dry weight was obtained with cow manure (0.093 g/m 2 ) and lowest with PK treatments (0.035 g/m 2 ). The highest flower dry weight was obtained with NPK and the lowest with N and PK application (0.92 and 0.33 g/m 2 ), respectively. Stigma dry weight has a stronger correlation with flower number compared to flower dry weight.

Superabsorbent polymers (SAPs) have shown to be quite effective and useful in acting as a reservoir for water and some nutrients in arid and semiarid regions. There are many studies in Iran that have been performed in relation to SAPs and their useful application in agriculture; however, there is still a lack of its applied definition in arid regions. Therefore, this study was conducted with the aim of doing a meta-analysis of the results of studies conducted in Iran and answering a general question about whether the application of SAPs has been effective in enhancing the production or not, and if so, how much of SAP is recommended. To conduct this research, articles published during 2006–2016 on the subject of the effects of different rates of SAP application on yield and yield components of crops (including cereals, legumes, and medicinal and grassland plants) were investigated. The results of the meta-analysis showed that the mean consumption rate of SAPs for cereals, legumes, and medicinal and grassland plants was 83, 322, 1031, and 210 kg ha−1, respectively, and that, at these SAP application rates, the mean seed yield in cereals, medicinal plants, and legumes increased by 15.2, 12.6, and 38% (equivalent to 1059, 345, and 452 kg ha−1), respectively, compared with the control. Dry matter response to superabsorbent application was slower compared with the seed yield response. The mean consumption of 83 kg ha−1 of superabsorbent for cereals increased seed yield by 15.2% on average. According to the results, it seems that the application of 100 kg SAP ha−1 is the most appropriate rate for increasing seed and dry matter yields and satisfying economic aspects. These study findings may shed light on the environment and socioeconomic concerns and improve efficacy and reduction of costs.