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.
Diagnostic petiole nntrieant norms and identification of yidd limiting lnutrrients in papaya (Capz'ea papaya) using diagnosis and recommendation integrated system
An experiment was conducted during 2004-05 to study the petiole nutrient norms using diagnosis and recommendation integrated system from 60 papaya (Carica papaya) gardens. A total of 300 samples were collected (sixth petiole from apex) to analyze for macro and micronutrients for establishment of the data bank. The whole population was divided into 2 sub-groups, namely low and high yielding by using diagnosis and recommendation integrated system and thus selected 45 nutrient expressions as diagnostic norms. These expressions had shown higher variance and lower coefficient of variation that are found to have greater diagnostic precision, viz N/P (6.368), N/K (0.571), Mg/N (0.899), N/Zn (0.045), Ca/Mn (0.062), Ca/Zn (0.115), Mg/Zn (0.039) and S/Zn (0.010) etc. The nutritional balance index indicates the overall imbalance of the nutrient-based on sum of the indices irrespective of sign. The diagnosis of nutrient imbalance through diagnosis and recommendation integrated system indices indicated that the most common yield-limiting nutrient is zinc, followed by potassium. In addition, 5 nutrient ranges have been derived using mean and standard deviation as low, deficient, optimum, high and excess for each nutrient to serve as a guide for diagnostic purpose. The optimum N ranged from 0.91 to 1.44%, P from 0.12 to 0.28%, K from 2.22 to 3.75%, Ca from 2.65 to 4.19%, Mg from 0.67 to 1.37% and S from 0.18 to 0.37%. Among the micronutrients the optimum Zn ranged from 17 to 40 ppm, Fe from 33 to 92 ppm, Mn from 34 to 60 ppm and Cu from 6 to 12 ppm for papaya.
Effect of cutting management and nitrogen levels on biomass production and proximate quality of barley (Hordeum vulgare) in saline soil
A field experiment was conducted during the winter (rabi) seasons of 1997–1998 to 1999–2000 on an alluvial loamy sand saline soil at Hisar, to find out the effect of cutting management and nitrogen levels on biomass production and proximate quality of barley (Hordeum vulgare L). Dry forage yield of barley was 6.3% higher when harvested once at 50% heading compared with 2 cuttings at 60 days of growth and 50% heading. The total biomass was 3.8% higher when harvested for grain purpose compared to the treatment in which the crop was first harvested for forage at 60 days and subsequently left for grain purpose. However, no significant differences were observed in the yield equivalents of barley grown for grain purpose or green forage and grain. Application of N significantly increased the yield from 22.5 q/ha with 60 kg N/ha to 29.3 q/ha with 80 kg N/ha. The protein and mineral matter contents were higher in grains (9.2 and 4.7%) and fodder (5.3 and 10.3%) harvested at the early stages than 9.0 and 4.6% in grain; and 4.9 and 9.8% in fodder at the late stage. However, the fibre and lignin contents were more in fodder harvested at later stages. With increasing levels of N application, the mineral matter remained unaffected, while the crude protein and lignin contents increased and fibre decreased in both fodder as well as grain.