Hot Water Soluble Boron Research Articles

Modeling and Spatial Variability of Soil Nutrients - A Case from Soil Health Card Project, India

Ascertaining and mapping soil nutrient data is crucial for governments to maintain soil health on farmlands. As part of the soil health card project, a total of 329 geo-referenced soil samples were collected from Thaticherla village, Anantapur mandal, Andhra Pradesh, India. These samples were analyzed for various soil properties such as soil pH, electrical conductivity (EC), organic carbon (OC), available nitrogen (N), available phosphorus (P), available potassium (K), available sulphur (S), DTPA extractable micronutrients (Fe, Mn, Zn, Cu), and hot water-soluble boron (B) at a depth of 0 to 15 cm. The results showed high variability (>35%) in coefficients of variation in Cu, EC, Zn, and B. The findings indicated positive correlation between Zn and Mn; N and OC; and OC and Zn. The data underwent logarithmic and Box-Cox transformations to achieve normalization. The ordinary kriging method was employed to analyze the spatial variability. The findings revealed that exponential model was appropriate for B, Fe, Mn, Zn, and OC; Gaussian for K; J-Bessel for N; K-Bessel for Cu, P, and S; stable for EC and rational quadratic for pH, respectively. The analysis showed a strong to weak spatial dependency. In the study area, the spatial variability maps exhibited deficiencies of 97%, 96% and 40% for N, OC and Zn, respectively. Therefore, it is urgent to apply suitable manures and fertilizers in the study area to address these issues. The study area exhibited significant variation in spatial patterns, emphasizing the importance of implementing field-specific plans for soil health and environmental management.

Status of Sulphur, Zinc and Boron in Onion Growing Soils of Dharwad Taluk, Karnataka, India

Survey was undertaken during rabi 2021-22, to study the sulphur, zinc and boron status in onion growing fields in selected villages of Dharwad taluk, Karnataka. One hundred surface soil samples were collected from selected ten villages of Dharwad taluk using GPS. The results revealed that soils were neutral to alkaline in reaction, low in total soluble salts, low to high organic carbon content, low in available nitrogen, medium in available phosphorus, potassium and sulphur and 49.00 and 77.00 per cent of the soils were deficient in DTPA extractable zinc and hot water soluble boron, respectively.

Influence of land type and cropping on the distribution of micronutrients in Ganges river floodplain soils of Bangladesh

The soils of Ganges River Floodplain (GRFP), an important crop growing zone of the country, are known to be widely deficient in micronutrients. The study was conducted to relate the distribution and the fate of soil micronutrients in relation to land type, soil properties and cropping practices in GRFP.A total of 52 locations were selected for sample collection from across GRFP, varied in land type, soil series and cropping pattern, and analysed for DTPA extractable iron (Fe), manganese (Mn), copper (Cu), zinc (Zn) and hot water soluble boron (B). Most of the samples were found deficient in Zn and B, while a moderate number of samples were Fedeficient. The major reason of micronutrient deficiency was found to be high soil pH. Among the four soil series studied, Ghior series was most deficient in Zn and B, implying pedogenic differences among the soils. Significant effect of contrasting land types on the distribution of soil micronutrients was observed although the effect was not consistent. The rice-rice cropping pattern was found to have slightly higher contents of Mn, Zn and B compared to rice-non-rice pattern which might be due to longer submergence period in the soils under rice-rice pattern. Dhaka Univ. J. Biol. Sci. 32(1): 91-105, 2023 (January)

Establishing Critical Leaf Nutrient Concentrations and Identification of Yield Limiting Nutrients for Precise Nutrient Prescriptions of Oil Palm (Elaeis guineensis Jacq) Plantations

African oil palm (Elaeis guineensis Jacq.) is a bulk feeder of nutrients. In this study, we aimed at devising strategies for efficient nutrient management in the oil palm plantations of the Krishna River basin located in Andhra Pradesh, India by assessing soil fertility status, establishing optimal leaf nutrient concentrations and identifying yield restrictive nutrients. In total, 67 oil palm plantations were surveyed from this area in 2020, soil samples were collected and analysed for different soil properties, including pH, EC, SOC, available P, K, S, exchangeable Ca and Mg, and hot water-soluble boron (HWB) in surface (from 0–20 cm depth), subsurface (from 20–40 cm depth) and deep (from 40–60 cm depth) soil layers. As per DRIS (Diagnosis and Recommendation Integrated System) indices estimated in this study, the order of requirement of nutrients is Nitrogen (N) > B > K > P > Mg for this area. Optimum leaf nutrient concentrations ranged between 2.07–4.29%, 0.13–0.27%, 0.52–0.94%, 0.44–0.76% and 44.97–102.70 mg/kg for N, P, K, Mg and B, respectively. In surveyed plantations, about 15, 6, 16, 9 and 12 percent of leaf samples had less than optimum concentration of N, P, K, Mg and B respectively. Nitrogen and Boron are the major yield limiting factors in this region. Leaf nutrient concentrations need to be maintained at the optimum ranges as estimated above for higher productivity in the Krishna basin area.

Soil fertility appraisal of some selected villages in Kirmira block of Jharsuguda District under western-central table land agro-climatic zone of Odisha, India

A soil fertility status inventory work was carried out in some villages of Kirmira block of Jharsuguda district located in the Western Central Table Land Agro Climatic Zone of Odisha, India. Results showed that soil pH ranged between 4.3 and 6.4 and electrical conductivity of the entire study area remained below 1 dSm-1. Soil Organic Carbon (SOC) content ranged between 0.17 to 0.88%. Available nitrogen content in these soils was found to be varied between 84.0 to 398.0 kg ha-1. Available Bray’s phosphorus content varied from 0.75 to 67.10 kg ha-1. Available soil potassium content varied widely from 90 to 500 kg ha-1. CaCl2 extractable soil sulphur varied from 0.14 to 12.49 mg kg-1. DTPA extractable micronutrients (Fe, Mn, Cu and Zn) varied from 32.62 to 192.20, 28.08 to 220.50, 0.48 to 2.86, and 0.56 2.38 mg kg-1 respectively. Hot water soluble boron content ranged from 0.13 to 0.88 mg kg-1. All the figures in the lower range were found in upland soils while the higher values for all the parameters were found in low land soils.

Characterization of Bt Cotton Growing Soils Producing Varying Cotton Yields in Dharwad and Haveri Districts of North Karnataka, India

Bt cotton is being cultivated on a wide range of soils in northern transitional zone of Dharwad and Haveri districts in north Karnataka. A field survey was conducted during kharif 2021-22 to study the physico-chemical properties and nutrients status of soil and Bt cotton productivity. A total of 153 locations were selected in Dharwad and Haveri districts. Surface soil samples were collected at fifty per cent flowering stage and kapas yield was recorded at first and second picking stages. In the study area, kapas yield ranged from 3.59 to 25.85 q ha-1 with a mean value of 15.95 q ha-1. Bulk density, soil porosity, maximum water holding capacity and moisture content at field capacity ranged from 1.12 to 1.70 Mg m-3, 35.85 to 57.74%, 34.08 to 76.27% and 13.63 to 45.76%, respectively. Soils were near neutral to slightly alkaline in reaction (6.60 to 8.80), non-saline (0.15 to 0.82 dS m-1), slightly to moderately high in free lime content (4.10 to 18.40%) and low to high in soil organic carbon (1.50 to 12.60 g kg-1) content. Available nitrogen, phosphorus (P2O5), potassium (K2O) and sulphur contents in soils of cotton fields ranged from 113.06 to 562.82, 10.50 to 89.56, 110.16 to 497.28 kg ha-1 and 5.06 to 25.67 mg kg-1, respectively. Similarly exchangeable calcium and magnesium contents in soils ranged from 10.10 to 35.24 and 2.98 to 17.01 cmol (p+) kg-1, respectively. DTPA extractable iron and zinc contents and hot water soluble boron content in soils ranged from 1.86 to 9.51, 0.20 to 1.10 and 0.10 to 0.75 mg kg-1, respectively. Nutrient indices showed that soils of the study area were low in available nitrogen, medium in available phosphorus, potassium and sulphur contents. Iron, zinc and available boron contents were deficient in soils.

Characterization of Spatial Variability of Micro Nutrients in Soils: Classical Vs. Geo-Statistical Approach

ABSTRACT The spatial variability characterization of micronutrients is needed for agricultural quality produce and environmental safety. However, study on this aspect is weakly implicit. In present study, Global Positioning System (GPS)-based 283 surface soil samples were collected and analyzed for pH, electrical conductivity (EC), organic carbon (OC), and micronutrients. Classical results revealed that soils are slightly acidic pH, safe in EC, low to medium in OC, and non-calcareous. OC was in order of Typic Haplustalfs-Chromic Haplusterts (S8)>Vertic Ustochrepts-Chromic Haplusterts (S3)>Typic Haplustalfs-Typic Haplustalfs (S9)>Typic Haplustalfs-Typic Ustipsammarts (S7)>Typic Haplusterts-Typic Ustorthents (S6)>Vertic Ustochrepts -Chromic Haplusterts (S5)> Lithic Ustochrepts -Typic Haplusterts (S4)>Typic Haplusterts -Vertic Ustochrepts(S2)>Typic Haplusterts-Typic Haplusterts (S1). In soils, zinc (Zn) and hot water-soluble boron (HWS-B) in order of S4>S5>S7>S9>S3>S2>S8>S1>S6 and S1>S2>S3>S4>S5>S9>S6>S7>S8, respectively. Overall, about 54.06 and 9.89% soil samples to be deficient in Zn and HWS-B in study area, respectively. Geo-statistical results showed that the exponential model was best-fitted for pH, calcium carbonate (CaCO3), OC, Zn and HWS-B and spherical model for EC and iron (Fe). However, the circular model was fitted for copper (Cu) and Manganese (Mn). The pH, EC, OC Zn, Cu, and Fe fall between 26 and 71%, which exhibit moderate spatial dependency. However, CaCO3 and Mn show 81 and 76% Nugget/sill ratios, respectively. Variability maps also showed the prediction of micronutrients using geo-statistical method better than classical methods.

Evaluation of Different Extractants for Boron Estimation in Soils of Odisha and Andhra Pradesh

The present study was conducted to compare the four different extractants widely used in boron (B) determination in soils and to screen the most suitable extractant for acidic (Alfisols) and alkaline (Vertisols) soils of Odisha and Andhra Pradesh. A total of 200 surface soil samples were collected across two sites (100 from each site) representing different pH ranges. Hot-water-soluble boron (HWS-B) extraction procedure being the most widely used B determination procedure was kept as a benchmark in order to compare the B extracting efficiency by the extractants viz., 0.01 M Calcium Chloride (CaCl2), 1 N Ammonium acetate (NH4OAc) pH-7.0 and 0.01 M Barium Chloride. The mean values of hot water extractable B for acidic soils were 0.49 (mean between 0.18 and 1.50 mg kg-1), CaCl2 – 0.42 (mean between 0.14 and 1.52 mg kg-1), BaCl2 – 0.45 (mean between 0.10 and 1.68 mg kg-1) and NH4OAc – 0.60 (mean between 0.17 and 2.43 mg kg-1). The mean values of hot water extractable B for alkaline soils were 1.87 (mean between 0.71 and 4.79 mg kg-1), CaCl2 – 1.57 (mean between 0.45 and 5.43 mg kg-1), BaCl2 – 1.37 (mean between 0.52 and 4.15 mg kg-1) and NH4OAc – 1.92 (mean between 0.85 and 8.33 mg kg-1) in acidic and alkaline soils respectively. The coefficient of variation for extractable B varied from 53.0 to 66.6 and 42.7 to 55.7 in acidic and alkaline soils respectively. The variation in B extracting efficiency in both the types of soils was found in the order: Hot water > Hot CaCl2 > BaCl2 > NH4OAc. Authors conclude that amongst all the compared extractants, 0.01 M CaCl2 extraction may be an adequate procedure for B determination in both the acidic as well as alkaline soils.

Yield and yield attributes of black gram (Vigna mungo L. Hepper) as influenced by phosphorus and boron in acid Inceptisol

A field experiment was conducted to investigate the effect of phosphorus and boron on yield and yield attributes of black gram. Four levels of phosphorus (0, 25, 50, 75 kg ha-1) and four levels of boron (0, 0.5, 1.0, 1.5 kg ha-1) were laid in split plot design with three replications. . The native soil had a pH 4.99, E.C. 0.42 dS m-1, organic carbon 1.32%, available nitrogen 251.35 kg ha-1, available phosphorus 13.68 kg ha-1, available potassium 233.24 kg ha-1 and hot water soluble boron 0.054 ppm. The results revealed that application of phosphorus and boron have a synergistic effect on yield, content and uptake in seed and straw of black gram. Significant highest seed yield was found when 50 kg P2O5 ha-1 along with 1.5 kg B ha-1. Significant plant height at 30 DAS (20.04 cm) and 60 DAS (39.31 cm) was found with the application of P50B1.5 whereas at maturity, the plant height was recorded maximum (43.01 cm) at P50B0.5. Whereas, highest number of pods per plant was recorded with combination of 75 kg P2O5 ha-1 and 1 kg B ha-1 (19.89) and lowest was recorded in control (11.93) where no phosphorus and boron has been applied. The highest seed index was obtained with combination of as 50 kg P2O5 ha-1 and 0.5 kg B ha-1 as 4.64 whereas, lowest as 2.54 in control respectively.

Response of black gram (Vigna mungo L. Hepper) to phosphorus and boron fertilization in acidic soil of Meghalaya

A field experiment was conducted to understand the response of black gram (Vigna mungo L. Hepper) to phosphorus and boron fertilization in acidic soil of Meghalaya. For this, four levels of phosphorus (0, 25, 50, 75 kg P2O5 ha-1) and four levels of boron (0, 0.5, 1.0, 1.5 kg B ha-1) were tested in field with sixteen treatment combinations and replicated thrice in split plot design. The native soil had pH 4.99, E.C. 0.42 dS m-1, organic carbon 1.32 percent, available nitrogen 251.35 kg ha-1, available phosphorus 13.68 kg ha-1, available potassium 233.24 kg ha-1 and hot water soluble boron 0.054 ppm. The results revealed that application of phosphorus and boron had synergistic effect on growth and yield of black gram. The plant height of black gram increased with crop development stages i.e. 30 DAS, 60 DAS and at maturity. Increasing phosphorus and boron doses also increased plant height over control at all crop development stages i.e. 30 DAS, 60 DAS and at maturity.The highest plant height at maturity stage under different phosphorus doses was recorded at 75 kg P2O5 ha-1 as 43.43 cm. However, the significant increase in plant height was observed up to 50 kg P2O5 ha-1 with 42.89 cm. Similarly, under different boron doses, the highest plant height (42.60 cm) was observed at 1.5 kg B ha-1 whereas, the lowest plant height was recorded in control plots of P and B as 36.58 and 38.17 cm, respectively at maturity. The seed yield of black gram increased with increasing phosphorus and boron doses. The highest seed yield (10.12 q ha-1) among different phosphorus doses was observed at 75 kg P2O5 ha-1. However significant increase in seed yield was recorded up to 50 kg P2O5 ha-1 with 9.52 q ha-1. Similarly, in case of boron, the significant increased seed yield was observed up to 1.0 kg B ha-1 (9.13 q ha-1) yet the highest seed yield was recorded as 9.43 q ha-1 with 1.5 kg B ha-1. The interaction effect of phosphorus and boron on seed yield was also found significant. The lowest seed yield was observed in control at P0B0 (5.56 q ha-1) and significantly high seed yield was observed at P50B1.5 (10.35 q ha-1) at phosphorus within boron, and in boron within phosphorus, it was recorded 11.03 q ha-1 at P75B1.

Delineation of boron status in Tirunelveli district of Tamil Nadu using GIS and GPS techniques

A study was undertaken in Tirunelveli district of Tamil Nadu with a view to assess the Boron status of soils at block level. A sum of 1,798 geo-referenced surface soil samples from nineteen blocks of Tirunelveli district representing different soil units as per the soil map prepared on 1:50,000 scales was collected randomly at 0-15 cm depth using Global Positioning System. The soil samples were analysed for available hot water soluble boron and the hot water soluble boron content varied from 0.01to 5.52 mg kg-1 soil. Analytical results and the GPS data was used for the preparation of thematic maps showing spatial distribution of micronutrients status block wise in the district. Locations of soil sampling sites of Tirunelveli district were marked on base map on 1: 50,000 scales prepared from State Revenue Maps and digitized using Arc-info GIS. The delineation study thus clearly indicates that, the hot water soluble boron was found to be low in Pappakudi and Cheranmahadevi blocks and in rest of the blocks it exhibited medium to high status.

Delineation and mapping of micronutrients status in the rice soils of Kasargode district of Kerala

Micronutrient deficiency in soil has become widespread in recent years and has resulted in low crop yields. Information on micronutrient status of rice soils is very much relevant for identifying constraints in rice production and to develop judicious fertilization to attain sustained productivity. The midland rice fields in Kasargode district constitute the drainage basins of hills and hillocks. Soil is lateritic and acidic in nature with high accumulation of reduced forms of iron and manganese and invariably poor in micronutrients boron, copper and zinc. In the present investigation 3500 surface soil samples were collected from selected 175 paddy fields of Kasargode and assessed for extent of soil acidity and available (0.1N HCl extractable) micronutrient status. Soil acidity is a serious constraint in these soils, which are very strongly acidic to neutral in reaction with pH values ranged from 4.21to 7.44. The content of 0.1 N HCl extractable Fe, Mn, Zn and Cu in soil varied from 52.21 – 414.9, 12.21 – 54.80, 0.66 – 38.5, 0.18 – 36.5 mg kg -1 respectively and hot water soluble boron varied from 0.027 – 0.948 mg kg -1. The available copper and zinc were found to be adequate and hot water soluble boron was deficient in these soils. The soil available iron and manganese was found to be excess and iron toxicity (> 200 mg kg -1) problem was also observed in some soils of the study area.

Soil fertility status of some villages in Sader block of Balasore district under North Eastern coastal plain agro climatic zone of Odisha, India

A soil fertility status inventory work was carried out in some villages of Sader Block belonging to Balasore district located in the North Eastern coastal plain Agro Climatic Zone of Odisha, India. Results showed that Soil pH ranged between 5 and 8.1. Soil Organic Carbon (SOC) content ranged between 0.43 to 13.1 g kg-1. Available nitrogen content varied in between 57.5 to 285 kg ha-1. Available phosphorus content varied from 0.7 to 31.5 kg ha-1. Available potassium content varied widely from 40 to 558 kg ha-1. DTPA extractable micronutrient (Fe, Mn, Zn and Cu) varied from 36.8 to 150, 10.8 to 38.9, 0.2 to 0.8 and 1.3 to 2.05 mg kg-1 respectively. Hot water soluble boron content ranged from 0.08 to 1.94 mg kg-1. Most of lower range were found in upland soils while the higher values for all the parameters were found in low land soils.

Depth-wise Distribution of boron in Relation to Soil Properties in South-West Punjab

The soils of Punjab are coarse textured and low in organic matter, therefore leaching of boron (B) beyond the root zone is more likely to occur in these soils. To study the depth-wise B availability in different soil types , samples were collected (0-15 cm, 15-30 cm, 30-60 cm and 60-90 cm) depth from soils representing Ustic Torripsamments, Typic Ustipsamments and Ustochreptic Camborthids. The highest (3.94 mg kg-1 soil) of hot water soluble boron (HWS-B) was observed in Ustochreptic Camborthids followed by Typic Ustipsamments (2.40 mg kg-1 soil) and Ustic Torripsamments (2.03 mg kg-1 soil). In general, hot water soluble B decreased with depth to the tune of 41.8, 35.4 and 36.4 per cent in Ustic Torripsamments, 16.2, 15.0 and 31.2 per cent in Typic Ustipsamments and 17.2, 29.1 and 39.1 per cent in Ustochreptic Camborthids, respectively. Significant positive correlations of HWS-B were observed with pH, organic carbon of soil and negative with CaCO3.

Status of Sulphur and Boron in Soils of North Gujarat Region of India

The soils of North Gujarat region's were assessed for its Sulphur and Boron status due to its visible deficiency in plants. Study was conducted in three districts viz., Sabarkantha, Mehsana and Patan from which 60, 110 and 52 villages were selected and soils samples were collected with geo-tagging. A total of 1332 surface soil samples (Sabarkantha 360, Mehsana 660 and Patan 312) were collected from these respective districts. Analysis of these soil samples showed a wide variation in soil pH (6.04-9.72) from slightly acidic to alkaline. Organic carbon (OC) content ranged from 1.0 to 7.1 g kg-1, about 90, 65 and 74% of soil samples were found to be under the low OC in Mehsana, Sabarkantha and Patan districts, respectively. Available S content ranged from 1.7 to 68.5 mg kg-1 with a mean value of 15.6, 14.7 and 14.9 mg kg-1 in Mehsana, Sabarkantha and Patan districts, respectively. S deficiency in soils of all three districts was 18.1, 25.5 and 16.9 per cent, which appeared in medium-fertility class level as per Nutrient Index Value (NIV). The high magnitude of S deficiency was noticed in soils of Idar taluka (43.9 %) followed by Khedbrahma taluka (40.9%) of Sabarkantha district, showing medium-fertility class. Further, these samples were also found deficient in hot water-soluble boron (HWS-B) and it ranged from 0.06 to 3.12 mg kg-1 with a mean value of 0.44, 0.45 and 0.44 mg kg-1 in districts of Mehsana, Sabarkantha and Patan, respectively. The NIV indicated B fertility level of low to high. Per cent deficiency of B recorded about 29.4, 17.9 and 19.2 per cent in all three districts. A large scale of B deficiency was noticed in Satlasna taluka (52.4 %) of Mehsana district, which showed low fertility class.

Soil fertility, leaf nutrient concentration and yield limiting nutrients in oil palm (Elaeis guineensis) plantations of Surat district of Gujarat

A survey was conducted for assessment of soil fertility status, leaf nutrient concentration and identification of yield limiting nutrients in twenty six oil palm (Elaeis guineensis Jacq.) plantations in Surat district of Gujarat. Soil pH, electrical conductivity (EC), organic carbon (OC), available potassium (K) (NH4OAc-K), available phosphorus (P) (Olsen-P), exchangeable calcium (Ca) (Exch. Ca) and magnesium (Mg) (Exch. Mg), available sulphur (S) (CaCl2-S) and hot water soluble boron (B) (HWB) content in surface (0-20 cm depth) and subsurface (20-40 cm depth) soil layers varied widely. 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 area was found to be K > nitrogen (N) > B > P > Mg. Optimum leaf nutrient ranges as per DRIS norms varied from 2.63 to 2.85%, 0.16 to 0.18%, 0.56 to 0.88%, 0.34 to 0.84% and 9.10 to 32.5 mg/kg for N, P, K, Mg and B respectively. On the basis of DRIS derived optimum ranges, 65, 31, 35 and 8 per cent leaf samples had less than optimum concentration of N, P, K and B respectively. The optimum ranges developed could be used for efficient nutrient management.

Assessment of soil boron availability in apple orchards using different extractants

Soil analysis for boron is vital as the range between its deficiency and toxicity is quite narrow and its application slightly above the optimum level may prove toxic to plants. In present study, the extractability of various extractants was assessed in relation to the physicochemical properties of soils. Soil sampling was carried out in 30 orchards in district Kulgam, Kashmir. Four extractants widely used to determine plant-available boron from either acidic or alkaline soils were used. The hot-water-soluble boron (HWSB) extraction procedure was used as a benchmark to observe relative variation in available boron in alternate extractants like calcium chloride-mannitol (CaCl2-mannitol), ammonium acetate and diethylene-triaminepenta-acetic acid-sorbitol (DTP Asorbitol). A significant correlation was found for available B among all the extractants tested, the strongest correlation (r = 0.975** at P≤0.01) was observed between HWSB and DTPA-sorbitol and hence it may substitute the hot water extraction method for estimating plant-available B.

Soil Nutrient Status and Leaf Nutrient Norms in Oil Palm (Elaeis Guineensis Jacq.) Plantations Grown in the West Coastal Area of India

ABSTRACTOil palm (Elaeis guineensis Jacq.) 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 64 oil palm plantations in the state of Goa lying in the west coastal region of India. Soil pH, electrical conductivity (EC), organic carbon (OC), available potassium (K) (ammonium acetate-extractable K) (NH4OAc-K), available phosphorus (P) (Bray’s-P), exchangeable calcium (Ca) (Exch. Ca) and magnesium (Mg) (Exch. Mg), available sulphur (S) (calcium chloride-extractable S) (CaCl2-S), and hot water soluble boron (B) (HWB) in surface (0–20 cm depth) soil layers ranged from 4.25 to 6.77, 0.05 to 1.06 dS m–1, 5.07 to 48.4 g kg–1, 58.1 to 1167 mg kg–1, 1.80 to 415 mg kg–1, 200 to 2997 mg kg–1, 36.0 to 744 mg kg–1, 3.00 to 87.7 mg kg–1 and 0.09 to 2.10 mg kg–1, respectively. Diagnosis and Recommendation Integrated System (DRIS) norms were established for different nutrient expressions and were used to compute DRIS indices. As per DRIS indices, the order of requirement of nutrients in the region was found to be P > Mg > K > nitrogen (N) > B. Optimum leaf nutrient ranges as per DRIS norms varied from 1.64 to 2.79%, 0.36 to 0.52%, 0.37 to 0.75%, 0.89 to 1.97%, 0.35 to 0.63%, 0.89 to 1.50%, 3.10 to 13.9 mg kg−1, 7.50 to 32.2 mg kg−1, 35.0 to 91.1 mg kg−1, 206 to 948 mg kg−1, and 895 to 2075 mg kg−1 for N, P, K, Ca, Mg, S, B, copper (Cu), zinc (Zn), manganese (Mn), and iron (Fe) respectively. On the basis of DRIS-derived sufficiency ranges, 14, 5, 11, 6, 6, 6, 8, 2, 3, 6, and 16% of leaf samples had less than optimum concentrations of N, P, K, Ca, Mg, S, B, Cu, Zn, Mn, and Fe respectively. The optimum ranges developed can be used as a guide for routine diagnostic and advisory purpose for balanced utilization of fertilizers.

Distribution variability of soil properties of oil palm (Elaeis guineensis) plantations in southern plateau of India

The present study was carried out to assess distribution variability of soil properties like pH, electrical conductivity (EC), organic carbon (OC), available potassium (K) (NH4OAc-K), phosphorus (P) (Olsen-P), exchangeable calcium (Ca) (Exch. Ca) and magnesium (Mg) (Exch. Mg), available sulphur (S) (CaCl2-S) and hot water soluble boron (B) (HWB) of oil palm (Elaeis guineensis Jacq.) plantations in southern plateau region of India. The mean values of soil pH, EC(dS/m), OC (g/kg), NH4OAc-K (mg/kg), Olsen-P (mg/kg), Exch. Ca (mg/kg) , Exch. Mg (mg/kg), CaCl2-S (mg/ kg) and HWB (mg/kg) were 6.94 ± 1.19, 0.53 ± 0.47, 11.6 ± 5.60, 179 ± 107, 92.9 ± 50.6, 820 ± 326, 159 ± 58.9, 21.8 ± 14.9 and 5.81 ± 2.53 respectively in surface (0 to 20 cm) soil layers. Geostatistical analysis revealed that surface soil properties had circular, Gaussian, spherical, and exponential best fit models and were influenced by intrinsic, extrinsic and both intrinsic and extrinsic factors. The wide spatial variability of soil properties warrants site specific nutrient management for higher oil palm production.

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.