Azarian Journal of Agriculture
Volume:3 Issue: 2, Apr 2016

Stemphylium species are pathogenic to a number of crops under broad geography and diverse environments. Stemphylium blight of lentil (Lens culinaris Medik) caused by Stemphylium botryosum Walr is becoming a serious emerging threat to lentil cultivation and become widespread throughout major legume growing areas in Nepal. Lentil was sown in different dates to observed incidence and severity of stemphylium blight in Rampur, Chitwan during two consecutive years 2012-2014. Lentil seeds sown up to middle of November escaped the disease severity and also resulted higher yield compared to other dates. Disease severity increased with the advancement of sowing date from November 1 to December 21 with decreased yields. The trends of disease development were similar in both years. The maximum and minimum temperatures, total rainfall and sunshine hour ranging from 22.42-24.23°C (mean 23.32°C), 4.12-13.00°C(mean 8.56°C), 9.6-30.5mm (mean 24.85mm) and 200.05-309.85 hour (mean 254.95 hour) respectively were favorable for disease development. A multiple linear regression model with temperature, rainfall and sunshine hourswas developed to predict stemphylium blight disease severity on lentil plants.

This research was concluded at Chittagong Hill Tracts in Bangladesh to identify the effects of different hedge species and assess alley width in controlling soil erosion and crop yield. Hedgerow or alley cropping cultivation is very helpful in reducing soil erosion in the hilly area. In order to perform cataloguing the hedges and their alley, four hedge species such as Indigofera, Bogamedula, Pineapple and Napier were used. Three different slopes viz., gentle slope, moderate slope and steeps slope, two different crops like yard long bean and okra were used in this experiment. The experiment lay out was in Split Plot Design with three replications. Soil erosion was measured through spike lay out method. Wider alley width gives a better performance of yield. Grass species (Napier) responses better than tree/shrub species (Bogamedula and Indegofera) on crops yield. Performance of pineapple among all other hedge species on crop yield and soil loss reducing capacity was recorded the best on all slope gradients and alley width. More yields were gained from the managed plots by hedge, though the number of total plant was comparatively less in those plots than the controlled one. Slope gradients have got the most important role on crops yield and soil erosion factor. The highest yields and the lowest soil loss were recorded in gentle slope in comparison with moderate and steep slope respectively. Crops yield were significantly reduced with the increase of slope gradients.

Organic manures are safer sources of plant nutrients and a good source of micronutrients therefore; pot experiments were carried out to estimate some extractable iron contents as influenced by organic manure application in the soils of Lake Geriyo, Adamawa state, Nigeria. Two types of organic manures; poultry droppings, cow dung and control were used for the experiment. Three levels of organic manures; 5, 10 and15 tons per hectare (ton ha-1)and three sampling time (30, 60 and 90 DAS were laid down in a completely randomized (CRD) design replicated three times. Results obtained revealed that rate, type of organic manures and time of submergence significantly (P ≤ 0.05) changed Fe content in the soil. Mean extractable iron concentrations of 42.01, 56.13 and 24.63 mgkg-1 were recorded for ammonium oxalate extractable iron, Citrate Bicarbonate Dithionite extractable iron and sodium pyrophosphate extractable iron in the first experiment while 45.81, 59.29 and 28.89 mgkg-1 were recorded for the second experiment respectively. However, CBD which extracts both amorphous and crystalline Fe recorded the highest Fe contents throughout the treatments with poultry droppings applied pots recording superior values than that of cowdung manure. similarly, higher values of oxa-Fe and Pyro-Fe were recorded in both manures compared to the control. In conclusion poultry droppings may result in iron accumulation and toxicity hence should be used with caution in the soil of Lake Geriyo and similar soils to avoid serious soil reduction leading to iron toxicity and soil phosphorus antagonism.

The current research was directed at Lighvan watershed, northwest of Iran to investigate ETM+ data applicability for the Soil Organic Carbon (SOC) prediction. So, Ground Measurements (GM’s) of SOC was carried out in 225 points of study area and ETM+ data were downloaded from NASA’s website. Different linear and nonlinear regressions were applied to predict SOC using GM’s from whole study area and bare soil only to train the models. Results showed that ETM+ data was impractical for remote sensing of SOC within whole study area due to vegetation effects. Contrary, ETM+ data showed satisfactory accuracy for SOC prediction in bare soils with mean evaluating error (ER) of 18. 34 percent for evaluation stage. A first and second order polynomial between measured SOC and the reflectance of band 1 to 7 of the ETM+ data showed the highest accuracy for SOC prediction with ER of 14 % and R2 of 0.665 for the evaluation stage. Although, ETM+ data application for remote sensing of SOC were restricted by vegetation, it seems that EMT+ data showed enough accuracy for predicting SOC through bare soils.