Asian Journal of Soil Science and Plant Nutrition

The main objective of this study was to improve the growth of oil palm seedlings by using microbe plus to enhance phosphorous availability from rock phosphate under oil palm nursery was evaluated at Oil Palm Research Institute of Ghana, Kade-Kumasi. The study consisted of 16 treatments replicated 3 times in a 4 × 4 factorial experiment arranged in Randomize Complete Block Design. The factors tested were: Phosphate fertilizers (Phosphate only, triple superphosphate, super rock phosphate and Togo rock phosphate) and microbe plus rates (0, 50, 100 and 150%). Data was collected on leaf area, leaf area index and dry matter production. All data obtained were subjected to analysis of variance (ANOVA) using GENSTAT Version 11.1 (2008). The results showed that the P fertilizers and microbe plus applied alone or their interactions had no significant (P=.05) effect on leaf area and leaf area index values, however, dry matter produced was significantly (P=.05) different from each other. TSPMP₁₅₀ treated seedlings produced significantly (P=.05) the highest dry weight; 42% increase over the control (No phosphate and microbe plus). The complementary use of microbe plus with triple superphosphate or Senegal rock phosphate proved to be the best options in terms of the parameters measured than the triple superphosphate. Microbe plus can therefore be used in combination with rock phosphate to improve phosphate availability. Field experiment is suggested to validate the effect of microbe plus and these rock phosphates on the performance of oil palm, whereas, additional studies with different application rates, both at nursery and at the field, are recommended.

Olive tree is the favorable choice to cultivate in desert lands due to high stress tolerance of its tree. Although olive tree tolerates the low availability of water in the soil by means of morphological, physiological and biochemical adaptations, the Productivity and fruit quality of it decrease gradually with increasing water stress. So we have initiated this study to follow up the effect of spraying Lithovit (Ca CO₃ & Mg CO₃) on the productivity and fruit quality of Picual and Manzanello olives which exposure to different irrigation levels. Four concentrations of Lithovit were sprayed on olive (Olea europaea var. Manzanello) trees (0, 2, 4 and 6 g/L) under three irrigation levels (50, 75 and 100% of evapotranspiration for crop “ETc”) during 2017, 2018 seasons.

Spraying Lithovit at 6 g/L recorded the highest values of all fruit physical characteristics of both cultivars in the two seasons. Furthermore, 2 g/L had the highest values of retained fruit percentage of both cultivars which led to increase the yield in the first and second seasons. Concerning irrigation levels, the values of fruit physical characteristics of both cultivars were the lowest values with applying 50% of ETc irrigation level. These values increased with decreasing water stress in the first and second seasons. Concerning retained fruit percentage and yield of Picual and Manzanello, the most promising level of irrigation was 75% of ETc level because it recorded the highest values of yield. Moreover 100% of ETc enhanced the fruit quality.

Pots experiment were carried out in green house of National Research Centre, Dokki, Egypt, to study the effect of potassium and humic acid application to minimize the adversely effects of soil salinity on pea plants. Pots were divided into three main groups of soil salinity at levels (2.84, 6.03 and 8.97 dS m^-1). These main groups were applied potassium sulfate at the rates 50 and 100 kg fed^-1. Foliar application of humic acid was applied at a rate of 0.2%. Data presented that the application of K₂SO₄ at a rate of 100 kg fed^-1 with humic acid a foliar spray at a rate of 0.2%, gave the highest values of plant growth parameters such as, Branch No., Leave No., Plant height, leaf area, Shoot fresh and dry weight. In addition to produce high chlorophyll a and b and carotene content as compared to other treatments and control under the different soil salinity levels. Application of K₂SO₄ (100 kg fed^-1) with foliar spray of humic acid under high and moderate soil salinity condition increased pod weight, seed weight, seed dry weight over application of 50 kg   fed^-1 and control. The highest values of studied chemical constituents in shoots and greens were obtained due to the application of potassium sulfate at100 kg fed^-1 with humic acid. The combined effects of potassium application and foliar spray of humic acid had a positive effect on increasing the ability of pea plant tolerance to soil salinity and increasing of growth and yield production under saline soil conditions.

Two pot experiments were carried out during the two successive seasons of 2010/2011 and 2011/ 2012 to apply mineral nitrogen and/or Azolla at different methods of addition with a reduction of mineral nitrogen fertilizer and its effect on vegetative growth, the yield of inflorescences, total phenolic concentration, antioxidant activity, nitrate and nitrite concentrations and the volatile oil concentrations and composition of chamomile inflorescences in sandy soil. Data indicated that dry Azolla (DA) treatments increased significantly plant height, number of branches/plant, shoot fresh and dry weights and number of inflorescences/plant against the rest treatments. It is clear that DA singly induced maximum growth parameters in both seasons and the reverse was true with fresh Azolla (FA) alone. It is obvious that DA achieved the highest total phenolic concentrations, antioxidant activity and volatile oil (VO) concentrations, and the opposite response was true for nitrate & nitrite concentrations. Addition of 50% ammonium nitrate to 50% FA or 50% Azolla extract as foliar (spray Azolla) SA have positive effect on chemical constituents except nitrate and nitrite concentrations. It is evident that the highest chamazulene and α ̶ bisabolol oxide ̶ B were achieved with DA and the reverse was true for α ̶ bisabolol oxide ̶ A. Dry Azolla treatment alone was the most efficient one in increasing the yield production with increment in active substances of chamomile plant in sandy soil.

Toxic pollutants and heavy metals in industrial effluents and city waste water are massive concern among the researchers, development worker, media personnel and policy makers. Keeping this in view-a pot experiment was conducted at the Bangladesh Rice Research Institute (BRRI), net house during T. Aman 2010 (wet season) and Boro 2011 (dry season) rice aimed to determining the effect of different industrial effluents on rice growth, yield and soil chemical properties. The irrigation effect of industrial effluents on rice production was more prominent in dry season (Boro) rice than wet season (T. Aman) rice. Perceptible changes in soil properties occurred through the effluents irrigation in rice-rice cropping pattern. Pharmaceutical and tannery effluents increased soil pH, EC, total N (%) available P (mg/kg). Exchangeable K, Ca, Mg and Na (cmol/kg) were increased due to irrigation with dyeing, pharmaceutical and tannery effluents. Dyeing, beverage, tannery and city waste water reduced percent soil organic carbon. Micronutrients (Zn, Fe, Cu and Mn) were increased significantly by the irrigation with dyeing, pharmaceutical and tannery effluents in both wet and dry season rice.  Heavy metals like Pb, Cd, Ni and Cr in soils were increased significantly through irrigation with effluents in rice-rice cropping pattern.