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ThesisItem Open Access CARBON AND PHOSPHORUS DYNAMICS IN SOIL IN RELATION TO NUTRIENT MANAGEMENT IN RICE-WHEAT SYSTEM(PAU Ludhiana, 2012) Seema Sharma; G. S., SaroaThe study comprised of two field and two laboratory experiments. In field experiment on organic and integrated nutrient management of basmati-wheat sequence, the effect of inorganic, organic and integrated nutrient management was studied on crop yield and soil properties. Water infiltration rate was highest and soil bulk density was lowest in recommended fertilizer + FYM (INM2) treatement. Total water stable aggregates (WSA) in the 0-15 cm soil depth ranged from 58.5 to 82.4 per cent; minimum WSA were observed in control and maximum in INM2 treatment. Among the aggregates 0.11-0.25 mm fraction constituted the greatest proportion and > 2 mm fraction constituted the least proportion. Maximum pH and EC were recorded in control plots and minimum in plots receiving 400 kg N ha-1 through FYM. Soil organic carbon (SOC), aggregate associated C, labile C and hot water soluble C was highest in FYM 400N treatment. Ammonical-N, nitrate-N, Olsen P, Bray I P, ammonium acetate extractable K, soil P fractions and total P in soil were highest in INM2 treatment and lowest in control. Grain yield, straw yield, NPK content and their uptake by basmati and wheat were maximum in INM2 treatment and minimum in control. Basmati and wheat grain yield were significantly correlated with soil P fractions and the highest correlation was observed with saloid-P. In the second experiment, effect of rock phosphate on crop yield and P fractions in soil under rice-wheat sequence was studied. Highest SOC, Olsen P, soil P fractions, ammonium extractable K and non-exchangeable K were recorded in rock phosphate (RP) and FYM treatment and lowest content of all these parameters was observed in control. Highest pH was observed in control P treatment and lowest in treatment where FYM was applied along with RP. Grain yield, straw yield, NPK content and uptake in grain and straw were also highest in plots recieving P from RP along with FYM. Grain and straw yield of both the crops were significantly correlated with all the soil P fractions (Sa-P, Al-P, Fe-P and Ca-P). Highest correlation of paddy grain yield was observed with Sa-P whereas wheat grain yield gave highest correlation with Al-P fraction and lowest with Ca-P. Rock phosphate gave almost similar crop yield and P availability in soil as that with SSP. In laboratory study I, P was extracted by different methods and the lowest amount of P was extracted with AB-DTPA and the highest with Bray-I method. Phosphorus extracted by Olsen, Bray-I, Morgan and AB-DTPA methods gave significant positive correlations with grain yield and nutrient uptake of paddy and wheat. In the soils from long-term experiments with different fertilization history, maximum P adsorption was observed in unammended soil and minimum in soils where FYM was applied alongwith chemical fertilizer. Contrarily, desorption was minimum in control plots and maximum in plots where organic sources along with inorganic fertilizers were applied. Adsorption data fitted well to both Freunlich and Lagmuir models. .ThesisItem Open Access Carbon and phosphorus dynamics in soil in relation to nutrient management in rice-wheat system.(PAU, 2012) Sharma, Seema; Saroa, G. S.The study comprised of two field and two laboratory experiments. In field experiment on organic and integrated nutrient management of basmati-wheat sequence, the effect of inorganic, organic and integrated nutrient management was studied on crop yield and soil properties. Water infiltration rate was highest and soil bulk density was lowest in recommended fertilizer + FYM (INM2) treatement. Total water stable aggregates (WSA) in the 0-15 cm soil depth ranged from 58.5 to 82.4 per cent; minimum WSA were observed in control and maximum in INM2 treatment. Among the aggregates 0.11-0.25 mm fraction constituted the greatest proportion and > 2 mm fraction constituted the least proportion. aximum pH and EC were recorded in control plots and minimum in plots receiving 400 kg N ha -1 through FYM. Soil organic carbon (SOC), aggregate associated C, labile C and hot water soluble C was highest in FYM 400N treatment. Ammonical -N, nitrate-N, Olsen P, Bray I P, ammonium acetate xtractable K, soil P fractions and total P in soil were highest in INM2 treatment and lowest in control. Grain yield, straw yield, NPK content and their uptake by basmati and wheat were maximum in INM2 treatment and minimum in control. Basmati and wheat grain yield were significantly correlated with soil P fractions and the highest correlation was observed with saloid-P. In the second xperiment, effect of rock phosphate on crop yield and P fractions in soil under rice-wheat sequence was studied. Highest SOC, Olsen P, soil P fractions, ammonium extractable K and non-exchangeable K were ecorded in rock phosphate (RP) and FYM treatment and lowest content of all these parameters was observed in control. Highest pH was observed in control P treatment and lowest in treatment where FYM was applied along with RP. Grain yield, straw yield, NPK content and uptake in grain and straw were also highest in plots recieving P from RP along with FYM. Grain and straw yield of both the crops were significantly correlated with all the soil P fractions (Sa-P, Al-P, Fe-P and Ca-P). Highest correlation of paddy grain yield was observed with Sa-P whereas wheat grain yield gave highest correlation with Al-P fraction and lowest with Ca-P. Rock phosphate gave almost similar crop yield and P availability in soil as that with SSP. In laboratory study I, P was extracted by different methods and the lowest amount of P was extracted with AB-DTPA and the highest with Bray-I method. Phosphorus extracted by Olsen, Bray-I, Morgan and AB-DTPA methods gave significant positive correlations with grain yield and nutrient uptake of paddy and wheat. In the soils from long-term experiments with different fertilization history, maximum P adsorption was observed in unammended soil and minimum in soils where FYM was applied alongwith chemical fertilizer. Contrarily, desorption was minimum in control plots and maximum in plots where organic sources along with inorganic fertilizers were applied. Adsorption data fitted well to both Freunlich and Lagmuir models.ThesisItem Open Access “Management of nitrogen in dry direct seeded rice for higher yield and nitrogen use efficiency”(Punjab Agricultural University, Ludhiana, 2012) Goyal, Deepak; Thind, Dr. H SThis investigation was carried out to find out the management of nitrogen in dry direct seeded rice (D-DSR) for higher yield and nitrogen use efficiency under field conditions. The experiment consisted of fifteen treatment combinations comprised of three N rates (120, 150, 180 kg N ha-1), four schedules of three rates of N application, two LCC treatments (LCC-3 and LCC-4) and zero - N control. The schedules of N application comprised of N application in three equal split doses applying first dose at basal or 14 DAS (0, 35, 63 and 14, 35, 63 DAS) and application of N in equal four split doses applying first dose at basal or 14 DAS (0, 28, 49, 70 and 14, 28, 49, 70 DAS). It is inferred that 120 kg N ha-1 when applied in three split doses was sufficient to produce optimum grain yield of dry direct seeded rice as further application of 150 or 180 kg N ha-1 did not increase the grain yield significantly. Among the different schedules of N application, three split doses were found to produce significantly higher grain yield than four split doses, at all the N levels. The higher grain yield in three split doses was accompanied by higher N uptake in grain, total N uptake, effective tillers and N translocation efficiency than N applied in four split doses. Harvest index, nitrogen harvest index and translocated N were found to be maximum at 120 kg N ha-1 when applied in three split doses applying first dose at 14 DAS. Agronomic efficiency, physiological efficiency and recovery efficiency were also highest at 120 kg N ha-1when applied in three split doses applying first dose at 14 DAS.ThesisItem Open Access Management of nitrogen in dry direct seeded rice for higher yield and nitrogen use efficiency(Punjab Agricultural University, Ludhiana, 2012) Deepak GoyalThis investigation was carried out to find out the management of nitrogen in dry direct seeded rice (D-DSR) for higher yield and nitrogen use efficiency under field conditions. The experiment consisted of fifteen treatment combinations comprised of three N rates (120, 150, 180 kg N ha-1), four schedules of three rates of N application, two LCC treatments (LCC-3 and LCC-4) and zero - N control. The schedules of N application comprised of N application in three equal split doses applying first dose at basal or 14 DAS (0, 35, 63 and 14, 35, 63 DAS) and application of N in equal four split doses applying first dose at basal or 14 DAS (0, 28, 49, 70 and 14, 28, 49, 70 DAS). It is inferred that 120 kg N ha-1 when applied in three split doses was sufficient to produce optimum grain yield of dry direct seeded rice as further application of 150 or 180 kg N ha-1 did not increase the grain yield significantly. Among the different schedules of N application, three split doses were found to produce significantly higher grain yield than four split doses, at all the N levels. The higher grain yield in three split doses was accompanied by higher N uptake in grain, total N uptake, effective tillers and N translocation efficiency than N applied in four split doses. Harvest index, nitrogen harvest index and translocated N were found to be maximum at 120 kg N ha-1 when applied in three split doses applying first dose at 14 DAS. Agronomic efficiency, physiological efficiency and recovery efficiency were also highest at 120 kg N ha-1when applied in three split doses applying first dose at 14 DAS. Keywords: Agronomic efficiency, Dry direct seeded rice, Grain yield, Nitrogen rates, Physiological efficiency, Recovery efficiency, Schedules of N application.Soil ScienceItem Open Access MULTIVARIATE CHARACTERIZATION OF SOIL FERTILITY AND ENVIRONMENTAL STATUS OF TWO BENCHMARK SOILS OF PUNJAB(Punjab Agricultural University, Ludhiana, 2012) HarshneetTwo benchmark soil series of Punjab, Gehri Bhagi and Nabha were studied for their physical and chemical properties with regard to fertility and environmental status. The pH (soil:water ratio 1:2) of Gehri Bhagi series varied from 8.2 – 9.4 and that of Nabha series varied from 7.3 – 8.9. In both the series, the pH decreased with increase in organic carbon (OC) content, which in turn increased with increase in clay content. Higher OC level (7.5 g kg-1) in Nabha series caused lower pH. The pH measured in CaCl2 was less spatially variable and better related to other parameters. Available phosphorus (P) status of Gehri Bhagi soils was lower than their Nabha counterparts notwithstanding higher total P content in Gehri Bhagi soils. Available potassium (K) was higher in Gehri Bhagi series and was linearly related to non-exchangeable K content. Micronutrient status of Nabha series was higher than Gehri Bhagi soils. Heavy metal content also followed the same trend. Available Zn was highly spatially variable. Principle component analysis (PCA) and factor analysis found texture factor most important fertility variable in both the soils. The PCA of heavy metals identified siderophile factor in Nabha series and Cadmium (Cd) solubility as the major factor in Gehri Bhagi series. Texture was the common factor for both the series. Minimum dataset analysis helped downsize number of variables from 59 to 14 in Gehri Bhagi series and to 17 in Nabha series. Cluster analysis helped group soils excavated for brick-kiln purposes and soils with high fertility status.ThesisItem Open Access Effect of different agricultural land uses on carbon sequestration in soils of sub-montaneous districts of Punjab(Punjab Agricultural University, Ludhiana, 2012) Rajwinder KaurThe present study was conducted to study carbon sequestration and its distribution in different soil organic carbon pools and to study soil aggregation and organic carbon storage in different sized aggregates under different land use systems in sub-montaneous districts of Punjab. Two sites selected for the study were Takarla and Mukerian and four land-use systems were selected viz. cropland, forestry, agro-forestry and grassland. Soil pH varied from slightly alkaline to moderate alkaline at Takarla while at Mukerian, soil pH was slightly alkaline. At both sites, pH was higher in grassland and EC was higher in cropland. Forest soils had higher silt and clay content at Takarla, while grassland possessed higher clay content at Mukerian. Bulk density at both sites was higher in cropland. Available N was higher in forestry (234.78 kg ha-1) at Takarla while in Mukerian, it was higher in grassland (199.70 kg ha-1). At both sites, cropland possessed highest available P and K. At Takarla, CEC was higher in cropland (10.83 Cmol kg-1) and in Mukerian, it was highest in forestry (12.65 Cmol kg-1). In surface soils at both sites, the water-stable macro-aggregates (WSA>2mm) were highest in grassland soils while the micro-aggregates (<0.25mm) were highest in agro-forestry at both sites. Micro-aggregates had lower C as compared to macro-aggregates at both sites in all land use systems. Soil organic carbon (SOC) was more in forestry (5.00 g kg-1) in Takarla and at Mukerian, grassland possessed higher amount (15.88 g kg-1). Among the SOC fractions, the POC was most dominant but LC and HWC showed vulnerability to land use change. At Takarla, HWC (490 mg kg-1), LC (1626 mg kg-1), IC (7.00 mg kg-1), total POC (3389 mg kg-1) and mineralizable C (48.6 mg kg-1) were more in agro-forestry and mineralizable N ( 109.7 mg kg-1) was more in forestry. At Mukerian, HWC (1370 mg kg-1), LC (1963 mg kg-1), IC (5.75 mg kg-1), total POC (7991.6 mg kg-1) and mineralizable C (85.8 mg kg-1) were more in grassland and mineralizable N (116.7 mg kg-1) was more in forestry. Soil properties and physical, biological as well as functional pools of SOM are strongly influenced by different agricultural land-use. Carbon sequestration seems to be more in agro-forestry at Takarla and in grassland at Mukerian. Climatic conditions / temperature also influenced carbon fractions at both sites. At Mukerian, values for carbon fractions were high as compared to Takarla, due to comparatively low temperature which decreases the rate of decomposition of soil organic matter in Mukerian.ThesisItem Open Access HUMUS-SOIL MINERAL INTERFACE IN ORCHARD AND FARM SOILS: NANOSCALE APPROACH(Punjab Agricultural University, Ludhiana, 2012) GURJIT SINGHClay-Humus complexes are pivotal for understanding long-term carbon retention in soils and founding protocols for nutrients, water and tillage management. Very little attempts were made to decipher the complexes formed under cultivation. Therefore, the study was undertaken for looking at bonding that different clay-minerals made with humus, imaging and deciphering interfaces of clay–humus complexes, and their association with land-use. For this, clays were extracted from surface soils of mango orchard (S1), guava orchard (S2) and ricewheat cultivated field (S3) of Bahadurgarh (30°21 45 N; 76°28 03 E; 255 m) in Punjab, India. Clays were untreated, organic matter (OM) was removed, CaCO3 was removed, and both OM and CaCO3 were removed. They were analyzed by chemical means, by Infra-Red Spectroscopy (IR), and by Scanning Electron Microscopy and Energy Dispersive Spectroscopy. IR spectroscopy identified dioctahedral and trioctahedral illites, and vermiculite, kaolinite, Al-chlorite, and montmorillonite in clays. Humic acids, amides, quinine, ketones and polysaccharides, and fulvic acids were identified in OM. S1 had phenol, and CH2 and CH3 groups, while S2 had aliphatic humic and fulvic acids, and aldehyde of humic acids, and carboxyl and ketonic groups in fulvic acid, and alkenes. The ratio of Oxydizable OC to clay-humus OC was: S1 (0.049) < S3 (0.054) < S2 (0.060). Micrographs portrayed uniform spread, irregular spread, and scattered lump of humus on various clayminerals. The humus from guava field had higher C content (15.60 by atom %) than humus from mango (12.1 by atom %), and cultivated fields (9.78 by atom %). Strong bond between clay minerals and humus deforms OH of clay minerals, and causes COO- anti-symmetric stretching in humus. Presence of phenol compounds in humus on clay surfaces tender resistance of these complexes to microbial degradation, and could be a crucial factor for N management in soils.ThesisItem Open Access AVAILABILITY AND DIFFERENT FORMS OF IRON IN SALT-AFFECTED SOILS OF MUKTSAR DISTRICT OF PUNJAB(Punjab Agricultural University, Ludhiana, 2012) Opinder SinghTen representative salt-affected soils from different parts of the Muktsar district of Punjab were studied for their morphological, physical and chemical characteristics and different forms of iron (Fe). The concentration of different forms of iron in the samples collected from different profile depths were estimated with the help of atomic absorption spectrophotometer. The texture of these soils varied from silty clay loam, silt, silt loam through loam to sandy loam whereas soil pH ranged from 8.3 to 10.2, 8.6 to 10.0 and 8.2 to 9.4 in the saline, sodic and saline-sodic soils, respectively. DTPA-Fe in these different soil profiles ranged between 1.08 to 31.2 mg kg-1 and followed the order as sodic < saline-sodic < saline soils. The SpAd-Fe content was reported the highest in the saline and the lowest in the saline-sodic soils. Iron adsorbed on oxide surfaces followed the order as MnOX-Fe < AFeOX-Fe < CFeOX-Fe whereas OM-Fe followed the order as saline-sodic > saline > sodic soils. The RES-Fe was highest in the saline soils and lowest in the saline sodic soils. The DTPA- Fe was significantly and near significantly positively correlated with EC and OC respectively. Also the DTPA-Fe showed significant positive correlation with MnOX-Fe and AFeOX-Fe. Similarly significantly negative correlation was observed between WSEX-Fe and CFeOX-Fe, SpAd-Fe and CFeOX-Fe, SpAd-Fe and OM-Fe. Results of the study showed that the mean total content of Fe in different soils was 2.10 per cent which is lower than the mean global value of 3.50 per cent.ThesisItem Open Access Effect of soil salinity on growth and physiological attributes of clonal Eucalyptus(Punjab Agricultural University, Ludhiana, 2012) Krishna Mohan BhargavaThe present investigation was aimed to study the effect of salinity on growth characters and water use efficiency of Eucalypts under different salinity levels was conducted at the Experimental area of department of Forestry and Natural Resources, Punjab Agricultural University, Ludhiana. The effect of five different salinity levels (Control, 5 dSm-1, 10 dSm-1, 20 dSm-1and 40 dSm-1) was investigated on three Eucalypts clones (Clone no. 288, 413 and 2070). Saline irrigation treatment of five levels was applied. Eventually two highest levels viz. 20 dSm-1and 40 dSm-1 leads to death of plants those were lethal levels for Eucalyptus spp. Remaining three levels viz. Control, 5 dSm-1, 10 dSm-1 were carried out and various attributes were recorded at different interval of growth. The results of the study revealed that salinity levels of 5 and 10 dSm-1 add significant negative effect on plant morphological characters viz. plant height, collar diameter, no. of branches, total leaf area, fresh shoot weight, dry shoot weight, fresh root weight, dry root weight, root shoot ratio and total biomass and physiological characters like photosynthesis, transpiration, water use efficiency were measured. When the salinity level increases from control to 5 dSm-1 there was reduction in mean value of plant height, collar diameter, and water use efficiency across all the clones by 33, 23 and 35 percent respectively. While further increment in salinity upto 10 dSm-1 leads to reduction in mean value across all the clones by 16, 25 and 31 percent respectively. After critical statistical analysis it was concluded that Clone no. 288 is best among all three clones in biomass production.
