Soil Nutrient Status and Leaf Nutrient Norms in Oil Palm (Elaeis guineensis Jacq.) Plantations Grown on Southern Plateau of India
Oil palm is a heavy feeder of nutrients and requires balanced and adequate supply of nutrients for optimum growth and yield. Information regarding soil nutrient status and leaf nutrient concentration is very much required for proper fertilizer application. Therefore, a survey was conducted for assessment of soil nutrient status and leaf nutrient concentration in 42 oil palm (Elaeis guineensis Jacq) plantations in the state of Karnataka, situated in southern plateau of India. In surface soil layers, soil acidity (pH), electrical conductivity (EC) and organic carbon (OC) content ranged from 4.91 to 8.74, 0.10 to 2.54 dS m−1 and 1.17 to 28.9 g kg−1 respectively. The values of available potassium (K) (NH4OAc–K), phosphorus (P) (Olsen-P) and exchangeable calcium (Ca) (Exch. Ca) varied from 31.2 to 386 mg kg−1, 7.69 to 242 mg kg−1 and 156 to 1273 mg kg−1 respectively. The concentration of exchangeable magnesium (Mg) (Exch. Mg), available sulphur (S) (CaCl2-S) and hot water soluble boron (B) (HWB) ranged from 52.8 to 307 mg kg−1, 2.25 to 73.5 mg kg−1 and 2.29 to 16.0 mg kg−1 respectively. Diagnosis and recommendation integrated system (DRIS) norms were established for different nutrient expressions and it was used to compute DRIS indices. As per DRIS indices, the order of requirement of nutrients in the region was found to be K > P > nitrogen (N) > B > Mg. Optimum leaf nutrient ranges varied from 2.24 to 2.97 %, 0.08 to 0.14 % and 0.78 to 0.91 % for N, P and K respectively, from 0.74 to 1.53 %, 0.25 to 0.98 % and 0.72 to 1.09 % for Ca, Mg and S respectively and from 5.71 to 31.0 mg kg−1, 7.42 to 12.9 mg kg−1, 33.6 to 58.6 mg kg−1, 82.5 to 681 mg kg−1 and 82.8 to 936 mg kg−1 for B, copper (Cu), zinc (Zn), manganese (Mn) and iron (Fe) respectively. On the basis of DRIS derived sufficiency ranges, 57, 24, 62, 3, 3, 9, 7, 5, and 26 % leaf samples were having less than optimum concentration of N, P, K. Ca, Mg, S, B, Cu and Mn respectively. The optimum ranges developed can be used as a guide for routine diagnostic and advisory purpose for balanced utilization of fertilizers.
Níveis críticos e faixas de suficiência de nutrientes derivados de métodos de avaliação do estado nutricional da palma-de-óleo
The objective of this work was to determine critical levels and nutrient sufficiency ranges for oil palm (Elaeis spp.), using methods for assessing the nutritional status of the plants. The methods of mathematical chance (ChM), diagnosis and recommendation integrated system (DRIS), and compositional nutrient diagnosis (CND), besides the critical level obtained by the reduced normal distribution (DNR), were used in productivity data and in nutrient content of 144 leaf samples of oil palm plantations in the state of Para, Brazil. The regressions of the DRIS and CND indexes with leaf nutrient contents were all significant, and the lowest coefficient of determination was found for N. The sufficiency range intervals obtained with the ChM, DRIS, and CND methods in the nutritionally balanced stands were, in general, narrower than the ones reported in the literature, with few concordant diagnostics, mainly for K. The critical levels obtained with DNR were within the nutritional range intervals obtained with the other methods. ChM, DRIS, CND, and DNR are suited methods for obtaining nutritional reference values, and they indicated N, Ca, S, Mn, and Zn as the nutrients with the highest frequency of deficiency in the evaluated oil palm orchards.
Comparison between Two Chemicals for Reducing Scale Formation in Reverse Osmosis Systems
In this present research was transacted with the calcium carbonate scale inhibition on the membrane surface of the reverse osmosis desalination system. Influence of changing feed solution flow rate (10-25)l/h, pH of the feed solution (6-10) on the recovery ,penetrate flow rate and total dissolved solid in (RO) system by using solution of calcium carbonate as feed solution was investigated, furthermore the effect of adding two types of scale inhibitor ,zinc chloride and polyamino polyether methylene phosphonate with difference concentration (2-8)mg/l for zinc chloride and (8-15) mg/l for polyamino polyether methylene phosphonate was calculated. The results showed that the permeate rate increases as the feed flow rate augmentation ,while it reducing with time, the total dissolved solids decreases as the feed flow rate increases while it increases with time and recovery rate decreases as the feed flow rate increases and it also decreases with time. It was concluded that the permeate rate decreases as the feed solution pH value increases and it cause high scale forming thus decrease the permeate TDS.By adding the scale inhibitor, it was found that the permeate rate and recovery rates increases as the concentration of inhibitor increases while the total dissolved solids decreases in the permeate with increasing the concentration of both inhibitors .It was discovered that Polyamino polyether methylene phosphonate more sturdy than zinc chloride as scale inhibitor for reverse osmosis desalination system in all concentrations was studied in this article.