تأثير السماد العضوي والاجهاد المائي في بعض خصائص التربة الفيزيائية ونمو وحاصل البطاطا في تربة جبسية و تربة رملية

Abstract

Field experiment was conducted in plastic pots during the fall season of 2017 in Falluja – Anbar Province (longitude 33 o 46'44E west and latitude 22o 21'27N north), to study the effect of organic-fertilizer and water stress on some soil physical properties , growth and yield of potato in sandy and gypsum soil. Drip irrigation system was evaluated before planting. uniformity coefficient, emission uniformity and discharge variations of emitters under operation pressures of 40, 50, 60 Kpa. It was relied on discharge of 3.76 L.h-1 at pressure of 60 Kpa. The effect of bio-fertiliser where poultry manure was added in two levels (0 and 2 %) mixed with soil in 0.30 m cm depth, and to study the water stress effect, irrigation was done at depletion rates of 40% and 60% of the available water. Watering timing was done depending on American Class A pan, half of irrigation depth was added and the 2nd half added after 6 hours. The experiment was applied in RCBD design in three replicates. Potato tubers (mid-early variety Revara, class A) were drilled on 20/9/2016 at a depth of 0.08 – 1.10 m. all crop and soil management was done as recommended. Bulk density, mean weight-diameter (MWD), saturated Hydraulic conductivity as physical properties of the soil, according to water consumption rate of the plant. Traits like plant height, leaf area, number of air-stalks, root mass and the total yield and water use efficiency was measured. Results were analysed using Genstat software, treatments compared at significant level of 5% using less significant difference (L. S. D). Obtained results can be summarized as bellow: 1- Bulk density increased after planting compared to its value before planting for all treatments, bulk density of gypsum soil was 1.46 Mgm-3 compared to 1.42 Mgm-3 of the sandy soil. Adding poultry manure led to reduction in bulk density value with 4.5% in gypsum soil b and 3.1% in sandy soil. Bulk density increased as moisture depletion increased where reached 1.46 Mgm 3 at 60% water depletion compared to 1.34 Mgm-3 at 40%. 2- Mean weight-diameter values for the gypsum soil were significantly superior compared to those of sandy soil, highest value reached 1.12 mm while the lowest was 0.69 mm. MWD values increased by adding poultry manures where reached 19.15 in gypsum soil and 10.14 in sandy soil. Irrigation at 60% depletion of available water led to decrease the MDW values with percentage of 17.81 in gypsum soil and 8.70 in sandy soil. 3- Saturated Hydraulic conductivity significantly decreased for both soils (32.0% and 17.7% in gypsum and sandy soil respectively) after planting compared to its value before planting and for all treatments. Highest value reached 12.3 cm.h-1 in sandy soil compared to 7.0 cm.h-1 in gypsum soil. Adding poultry manures with percent of 2% led to reduction in Saturated Hydraulic conductivity by 24.4% and 16.3% in both sandy and gypsum soil respectively. Saturated Hydraulic conductivity decreased as moisture depletion increased from 40% to 60% which reached 12.3 cm.h-1 at 40% depletion compared to 6.7 cm.h-1 at 60%. 4- Water consumption of potato reached 464.5 mm/season in sandy soil and 395.2 mm/season in gypsum soil. Volumes of added water to sandy soil reached 1549 m3 ha-1 while reached 1317.20 m3 ha-1 to gypsum soil. 5- Adding poultry manures by 2% led to increase available water in soil by 8.7% in sandy soil and 7.13% in gypsum soil. 6- Values of growth traits were superior for plants in gypsum soil compared to them in sandy soil where highest value of plant height reached 87 cm and leaf area reached value of 69 cm2 plant-1 , branches number increased by 35% in gypsum soil compared to sandy one, while root mass value was superior for plants in c sandy soil (13.2 gm plant-1 ) compared to gypsum soil (9.5 gm plant-1 ). 7- Poultry manures percent of 2% mixed with soil led to significant increase of growth traits of potato where plant height increased by 17.47% and 44.44%, leaf area increased by 18.97% and 28.46% and branches number reached 6.4 and 7.3 each plant while root mass decreased by 28% and 33% in gypsum soil compared to sandy soil respectively. 8- Growth traits values significantly reduced at irrigation at moisture depletion of 60% compared to the irrigation at 40% depletion of moisture, where plant height reached 63.5 cm and 74.1 cm in gypsum soil and reached 44.3 cm and 58.4 cm in sandy soil at 60% and 40% respectively. Leaf area reached 39.0 dcm2 compared to 58.0 dcm2 . Branches number reduced by 30.0% in gypsum soil and 16.7% in sandy soil. Root mass increased as moisture depletion increased and reached 13.2 gm in sandy soil and 29.5 gm in gypsum soil when irrigating at 60% depletion compared to 40% respectively. 9- The total yield of potato reached 34.010 ton ha-1 in sandy soil and 28.020 ton ha-1 ,in gypsum soil adding poultry manures increased the total yield significantly as the increasing percentage reached 20.7% in sandy soil and 30.0% in gypsum soil. Total yield values decreased as moisture depletion increased from 40% to 60% with reduction percent of 28.8% in sandy soil and 25.7% in gypsum soil. 10- Sandy soil had the best water use efficiency reached 21.950 kg m-3 compared to 21.273 kg m-3 . Adding poultry manures led to significant increase of water use efficiency values which reached 20.6% in sandy soil and 29.95% in gypsum soil, however, increasing moisture depletion percentage decreased the water use efficiency by 19.91% in sandy soil and 23% in gypsum soil.