• Authors:
    • Al-Ain, F.
    • Al-Chammaa, M.
    • Khalifa, K.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 43
  • Issue: 16
  • Year: 2012
  • Summary: A field experiment was carried out to study the effect of different rates of potassium (K) fertilizer [0, 50, 100, and 150 potassium oxide (K2O) ha(-1)] in the presence of increased supply of nitrogen (N) (120, 180, and 240 kg N ha(-1)) on cotton (Gossypium hirsutum L.) yield and the N and K use efficiencies using the N-15 isotopic dilution technique. Potassium fertilizer increased cotton yield, which was significant and more pronounced with the application of N in the high level (N3). The greatest cotton yield (6442 kg ha(-1)) was obtained in N2K3 treatment with an increase of 14% over the control. In addition, K fertilizer significantly increased N uptake efficiency in the N2 and N3 treatments. The greatest N uptake efficiency (98%) was in N2K3 treatment. The greatest K uptake efficiency (42%) was occurred in N3K1 treatment. In conclusion, the use of K fertilizer could be useful when growing cotton in soils of moderate to high N content to improve N uptake efficiency and consequently increase cotton yield.
  • Authors:
    • Soffianian, A.
    • Khodakarami, L.
  • Source: Journal of Science and Technology of Agriculture and Natural Resources,Water and Soil Science
  • Volume: 15
  • Issue: 59(B)
  • Year: 2012
  • Summary: Precision farming aims to optimize field-level management by providing information on production rate, crop needs, nutrients, pest/disease control, environmental contamination, timing of field practices, soil organic matter and irrigation. Remote sensing and GIS have made huge impacts on agricultural industry by monitoring and managing agricultural lands. Using vegetation indices have been widely used for quantifying net annual production on different scales. The aim of this study was to find a rapid method with acceptable precision for the identification and classification of agricultural lands under cultivation (wheat and barley, alfalfa and potatoes). We used multi-temporal AWiFS data and applied Boolean logic and unsupervised classification. Results indicated that Boolean logic approach had a higher accuracy and precision in comparison to unsupervised classification, although it is more complicated and time consuming.
  • Authors:
    • Rathore, P.
    • Singh, H.
    • Singh, K.
    • Gumber, R. K.
  • Source: Journal of Cotton Research and Development
  • Volume: 26
  • Issue: 1
  • Year: 2012
  • Summary: A field experiment was conducted at PAU, Regional Research Station, Faridkot during kharif 2009 and 2010 to evaluate the performance of two arboreum varieties (FDK 124 and LD 694 as check) under two plant geometries (67.5*45 and 67.5*60 cm) and three nutrient levels (i.e. 56.25, 22.5 kg NP/ha; 75, 30 kg NP/ha and 93.75, 37.5 kg NP/ha). New variety FDK 124 yielded 24.5 per cent significantly higher seed cotton yield (2814 kg/ha) as compared to LD 694 (2260 kg/ha) due to significantly more number of bolls. Pooled data further indicated that significantly higher seed cotton yield was recorded under closer geometry of 67.5*45 cm (2613 kg/ha) than wider plant geometry of 67.5*60 cm (2460 kg/ha). Though, yield attributing parameters such as bolls/plant were statistically improved in wider as compared to closer spacing but it could not compensate yield due to significantly higher plant population in the later case. Among nutrient levels, similar seed cotton yield was recorded with application of 93.75, 37.5 kg NP/ha (2688 kg/ha) and 75, 30 Kg NP/ha (2587 kg/ha) but both were significantly better than that of 56.25, 22.5 kg NP/ha (2335 kg/ha). So, 75, 30 kg NP/ha and plant geometry of 67.5*45 cm seemed to be ideal for new variety FDK 124 for realizing higher productivity under the specific agro climatic conditions of Faridkot.
  • Authors:
    • Li, C. J.
    • Tian, C. Y.
    • Mai, W. X.
  • Source: Australian Journal of Crop Science
  • Volume: 6
  • Issue: 5
  • Year: 2012
  • Summary: Long-term use of drip irrigation technology may lead to root degradation and affect shoot growth and yield. A field experiment was conducted to investigate above- and belowground growth responses to drip irrigation under mulch film (DI) in comparison to flood irrigation under mulch film (FI) in cotton. The monolith method was used to harvest roots at seven timepoints in the growth periods, and the root length, and shoot and root dry weight were measured. The total root length per plant in the 0-10 cm soil layer was higher under DI, whereas in the 30-60 cm soil layer roots were longer under FI. From 65 to 96 days after sowing (DAS), the rate of increase in root length was lower under DI than FI. Total root length decreased after 125 DAS under DI, and was mainly centered in the 0-40 cm soil layer and at distances of 30-70 cm from drip-lines. The shoot:root ratio at 125 DAS was higher under DI than FI, but at 160 DAS the shoot:root ratio abruptly declined under DI. The decline in root length under DI during advanced growth stages may be attributable to the higher root density in shallow soil layers and the increase in the shoot:root ratio. These results suggest that, it are important to increase yield of cotton plants under DI early development of a deep root system and initial control of shoot growth by regulation of water and fertilizer supply.
  • Authors:
    • Ghahderijani, M.
    • Pishgar-Komleh, S. H.
    • Sefeedpari, P.
  • Source: Journal of Cleaner Production
  • Volume: 33
  • Year: 2012
  • Summary: The aim of this research was to examine the energy consumption and CO 2 emission of potato production in three different farm size sin Esfahan province of Iran. For this purpose, data were collected from 300 farmers by a face to face questionnaire. The results revealed total energy consumption and GHG emission of 47 GJ ha -1 and 992.88 kg CO 2eq ha -1, respectively. The most significant energy consumer was chemical fertilizers (49%), especially nitrogen (40%) and followed by seed with share of 24%. The energy use efficiency, specific energy and energy productivity were determined to be 1.71, 2.12 MJ kg -1 and 0.47 kg MJ -1. The different cultivated area levels analysis revealed that, large farms used the least amount of energy input significantly. It was found that the contribution of indirect energy was higher than that of direct energy and also the proportion of non-renewable energy was more than renewable resources. The results of econometric model estimation revealed that the impact of seed, water for irrigation, diesel fuel and chemical fertilizer energy inputs were significantly positive on potato yield. The sensitivity analysis illustrated that the marginal physical productivity (MPP) value of chemical fertilizer, diesel fuel and seed energy were -1.78 and -1.63 and 1.54, respectively.
  • Authors:
    • Hussein, M. S.
    • Elsebai, M. N.
    • Rihan, M. K.
  • Source: Arab Universities Journal of Agricultural Sciences
  • Volume: 20
  • Issue: 1
  • Year: 2012
  • Summary: Egypt depends on the Nile River as a major source of water, it provides about 76.3% of its water requirements, other water sources provides about 23.7% of total water requirements. Agriculture sector is the main consumer of water in Egypt as it consumed about 85.9% of the total actual consumption of water in 2009. The main problem of the present paper is the decrease in the efficiency of water use in Egyptian agriculture. The objective of paper is to assess the efficiency of water use in agriculture in the old and new land Egypt through the use of partial efficiency measures. Results showed that in average of the cost of irrigation per feddan during the period (1998-2009), that was for winter crops in the old lands as follows: 85.3, 105.8, 119.3, 127.3 pounds/feddan for faba bean, sugar beet, alfalfa sustained, wheat at a cost of irrigation per feddan of which respectively. For summer crops in old land cost was about 114.7, 129.5, 139.8, 156.2, 217.8, 606.1 pounds/feddan at a cost of, sesame, soybean, peanut, corn, rice, sugar cane, respectively. For the winter crops in the new lands irrigation cost per feddan was about L.E 99.3, 169.0 for garlic and onion respectively. Summer crops in the new lands irrigation costs for watermelon, cucumber, potatoes, eggplant, peppers, and tomatoes were as follows: L.E 92.4, 133, 138.7, 139.8, 157.7, 194.3 pounds/feddan respectively. The results of the statistical analysis of partial-efficiency measures showed that, according to the criterion of net revenue from the water unit - winter crops on the old land as follows: alfalfa, wheat, faba bean, and sugar beet. As for the summer crops of old land the results showed of the statistical estimate of the partial-efficiency measures that peanuts, corn, sesame, sugar cane, rice, soybeans respectively. In the new lands the results of statistical analysis for the partial-efficiency measures, according to the standard net return of the water unit for winter crops were garlic followed by the first crop of onions. As for the summer crops, the results of statistical analysis of partial-efficiency measures, according to the standard net return of the water unit came summer crops in the new lands, were as follows: potatoes, tomatoes, watermelon, cucumber, eggplant, pepper. The results in general indicated the necessaries of reconsidering the present structure of cropping pattern to increase the efficiency of irrigation water use.
  • Authors:
    • Ellouz, R.
    • Guiderdoni, E.
    • Mieulet, D.
    • Azaza, J.
    • Zouari, N.
    • Ben-Ramdhan, W.
    • Ben-Saad, R.
    • Afif, H.
  • Source: Molecular Breeding
  • Volume: 30
  • Issue: 1
  • Year: 2012
  • Summary: We have recently isolated the AlSAP (stress-associated protein) gene from the halophyte grass Aeluropus littoralis and demonstrated that AlSAP expression improves tolerance to continuous salt and drought stresses in transgenic tobacco. To extend these findings to an important crop, we generated marker-free transgenic durum wheat plants of the commercial cv. Karim expressing the AlSAP gene. The integration and expression of AlSAP in T3 homozygous plants were ascertained by Southern, Northern and Western blotting respectively. AlSAP wheat lines exhibited improved germination rates and biomass production under severe salinity and osmotic stress conditions. Following a long-term salt or drought stress greenhouse trial, AlSAP lines produced normally filled grains whereas wild-type (WT) plants either died at the vegetative stage under salt stress or showed markedly reduced grain filling under drought stress. Measurements of the RWC (relative water content) and endogenous Na + and K + levels in leaves of AlSAP plants, showed a lower water loss rate and a higher Na + accumulation in senescent-basal leaves, respectively, compared to those of WT plants. Taken together, these results extend to cereals the high potential of the AlSAP gene for engineering effective drought and salt tolerance.
  • Authors:
    • Voltas, J.
    • Molist, M.
    • Guerrero, E.
    • Buxo, R.
    • Arab, G.
    • Ferrio, J.
    • Araus, J.
  • Source: Journal of Arid Environments
  • Volume: 86
  • Year: 2012
  • Summary: Modern Syria, and in particular the Middle Euphrates valley, has been occupied and overexploited since the beginnings of agriculture. Thus, the study of the economic and environmental characteristics of ancient settlements may offer new perspectives on the long-term effects of continuous agriculture in a fragile agroecosystem. In this work, we present a methodological framework that uses archaeological information to understand long-term effects of the extensification of agriculture in present-time arid areas. Specifically, we have compared the main economic features of a Neolithic site of the middle Euphrates, Tell Halula (ca. 10th millennium BP), with present-day data from the surrounding region. Population, crop distribution, cereal yields and arable land requirements during the first millennia after the emergence of agriculture were estimated from archaeological data and compared with a compilation of present-time official statistics and data derived from a field survey. We observed a trend towards a cereal-based farming during the Neolithic, associated to a decrease in the diversity of wild florae. This was accompanied by a growth in population during the earliest phases of the settlement (8200-7000 cal BCE), followed by a decline in population in the late phases (7000-5400 cal BCE), probably as a consequence of exceeding the capacity of the agroecosystem. A comparable situation to that found in early phases of Tell Halula was observed in modern communities, showing similar growth rates and a strong focus on cereal crops.
  • Authors:
    • Manukyan, R.
    • Asadi, H.
    • Nazmi, L.
    • Naderi, H.
  • Source: Canadian Journal of Soil Science
  • Volume: 92
  • Issue: 4
  • Year: 2012
  • Summary: In hilly landforms subject to long-term cultivation, erosion has denuded the upper slope positions of topsoil, and accumulated topsoil in the lower slope positions. Slope gradient and position effects aggregation processes, which in turn impact soil productivity. A field experiment was conducted to assess the tillage-induced soil displacement and its effects on the soil properties and barley ( Hordeum vulgare var. Sahand) biomass production for three different landscapes. The study was conducted on a hill slope seeded with barley (1.4-10.1° slope) located in the Mollaahmad watershed of the Ardabil province in northwestern Iran. For this purpose, soil samples were collected from four slope positions in a grassland as well as an agricultural field (dryland). A field experiment was conducted to evaluate the effects of slope gradient and position on barley growth and soil quality. Soil generally had lower organic carbon, available phosphorus, calcium carbonate equivalent, soil water content and mean weight diameter of soil aggregates in the farmland than the grassland, and in the upper slope positions than in the lower slopes. Significantly higher barley growth indices were associated with lower slope positions. Agronomic productivity of the soil was lowest for landscapes with the highest slope gradient. The relationships between tillage erosion and yield components were found to be significant. Spike weight and slope position had the largest contribution for the explanatory capacity of canonical variables (tillage erosion and yield components) estimated when compared with other parameters (slope gradient, dry matter, spike number, grain yield and 1000-grain weight). The findings in this study can be used as a tool to assist farmers, soil and water conservationists, and other policymakers in decision making regarding the use of lands.
  • Authors:
    • Sadeghi, H.
  • Source: International Journal of Agriculture: Research and Review
  • Volume: 2
  • Issue: 3
  • Year: 2012
  • Summary: Residue burning is a quick, labor-saving practice to remove residue that is viewed as a nuisance by producers in the most southern provinces of Iran. However, residue burning has several adverse environmental and ecological impacts. The burning of dead plant material adds considerable amount of CO 2 and particulate matter to the atmosphere and can reduce a lot of returned needed C and other nutrients to the soil. Whereas, crop residues incorporation can improve soil quality and reduce air pollution on a long term basis. However, where residues have been soil incorporated, farmers often have concern for reduced soil fertility from nutrient immobilization and problems for cultivation associated with slow rates of residues decomposition. The experiment was conducted as strip split plot with four replications. Horizontal plots were three crop residues rates (0, 750 and 1500 kg ha -1), vertical plots consisted of two dryland current barley cultivars (CVs) (Afzal and Reyhan), and sub-plots were three N rates (0, 40, and 80 kg N ha -1). Number of spike per plant, grains per spike, grains per plant and 1000-grain weight of both CVs significantly increased by N and residue rates increasing in both years. The lowest grain yield was obtained from 1500 kg ha -1 residue incorporation without N application showing the soil N imbalance. The optimum crop growth and the highest grain yield was achieved from the highest crop residues and N rates, indicating that the most reliable system for dryland barley production in the region is complete residues incorporation into the soil following disking, seeding with chisel seeder and application of 80 kg N ha -1.