Setia R.,University of Adelaide |
Marschner P.,University of Adelaide |
Baldock J.,University of Adelaide |
Baldock J.,CSIRO |
And 2 more authors.
Soil Biology and Biochemistry | Year: 2011
Net carbon dioxide (CO2) emission from soils is controlled by the input rate of organic material and the rate of decomposition which in turn are affected by temperature, moisture and soil factors. While the relationships between CO2 emission and soil factors are well-studied in non-salt-affected soils, little is known about soil properties controlling CO2 emission from salt-affected soils. To close this knowledge gap, non-salt-affected and salt-affected soils (0-0.30 m) were collected from two agricultural regions: in India (irrigation induced salinity) and in Australia (salinity associated with ground water or non-ground water associated salinity). A subset (50 Indian and 70 Australian soils) covering the range of electrical conductivity (EC) and sodium adsorption ratio (SAR) in each region was used in a laboratory incubation experiment. The soils were left unamended or amended with mature wheat residues (2% w/w) and CO2 release was measured over 120 days at constant temperature and soil water content. Residues were added to overcome carbon limitation for soil respiration. For the unamended soils, separation in multidimensional scaling plots was a function of differences in soil texture (clay, sand), SOC pools (particulate organic carbon (POC) and humus-C) and also EC. Cumulative CO2-C emission from unamended and amended soils was related to soil properties by stepwise regression models. Cumulative CO2-C emission was negatively correlated with EC in saline soils (R2 = 0.50, p < 0.05) from both regions. In the unamended non-salt-affected soils, cumulative CO2-C emission was significantly positively related to the content of POC for the Indian soils and negatively related to clay content for the Australian soils. In the wheat residue amended soils, cumulative CO2-C emission had positive relationship with POC and humus-C but a negative correlation with EC for both Indian and Australian soils. SAR was negatively related (β = -0.66, p < 0.05) with cumulative CO2-C emission only for the unamended saline-sodic soils of Australia. Cumulative CO2-C emission was significantly negatively correlated with bulk density in amended soils from both regions. The study showed that in salt-affected soils, EC was the main factor influencing for soil respiration but the content of POC, humus-C and clay were also influential with the magnitude of influence depending on whether the soils were salt affected or not. © 2010 Elsevier Ltd.
Verma S.L.,University of Adelaide |
Setia R.,Punjab Remote Sensing Center |
Marschner P.,University of Adelaide
Communications in Soil Science and Plant Analysis | Year: 2016
ABSTRACT: It is well known that compost amendment can improve soil phosphorus (P) availability, but there are few studies comparing the effect of one compost type on soil P pools of soils which differ in properties. The aim of this glasshouse experiment was to determine the effect of compost (derived from garden waste) application on P pools in soils with different properties planted with wheat. Four soils from two sites were used, with a heavier and a lighter textured soil from each site. The compost was applied as a 2.5 cm thick layer on the soil surface and wheat plants were grown for 63 days. The treatments also included soil without compost and plants. All pots were regularly watered. The soils were sampled on day 0 in the unamended soils and on day 63 in soil without compost and with compost, and plants after removal of the compost layer. Without and with compost the concentrations of most P pools were higher in the two heavier textured soils (16% and 35% clay) than in the two lighter textured soils (8% and 13% clay). Principal component analysis (PCA) showed that the concentrations of most P pools were positively correlated with organic matter, clay, and silt content of the soils. Only the concentration of water-soluble P was positively correlated with sand content. Compost addition increased the concentration of microbial P, sodium bicarbonate (NaHCO3)-Pi, sodium hydroxide (NaOH)-Pi, hydrochloric acid (HCl)-P, and residual P in all soils, whereas the concentration of NaHCO3-Po was reduced and the concentration of NaOH-Po little affected by compost addition indicating that P was transferred from the compost layer with watering. Compared with the unamended soil on day 0, the concentrations of microbial P, NaHCO3-Pi, NaOH-Pi, HCl-P, and residual P on day 63 were higher, whereas the concentrations of the two organic pools (NaHCO3-Po and NaOH-Po) were lower. This suggests mineralization of organic P pools and formation of inorganic P as well as microbial P uptake. These changes occurred in the unamended and compost-amended soils with greater increases over time in the compost-amended soils. It can be concluded that the size of the P pools is predominately affected by soil texture. Compost amendment increases P availability and microbial P uptake but also leads to the formation of less labile P pools such as HCl-P and residual P which could serve as plant P sources in the long term. © 2016 Taylor & Francis.
Setia R.,University of Adelaide |
Setia R.,Punjab Remote Sensing Center |
Rengasamy P.,University of Adelaide |
Marschner P.,University of Adelaide
Biology and Fertility of Soils | Year: 2014
Sorption is an important process for retention of organic carbon (C) in soils. The effect of Na+ and Ca2+ on sorption of organic C has been studied in salt-affected soils, but little is known about the effect of K+ and Mg2+ ions on sorption of water-extractable organic C (WEOC). The effect of Na+, K+, Ca2+ and Mg2+ ions on sorption of WEOC and its decomposition were investigated in a loamy sand (7.5 % clay) and a sandy clay loam (34.4 % clay). Salinity was developed with NaCl, KCl, MgCl2 or CaCl2 to obtain different concentrations of exchangeable Na+, K+, Ca2+ and Mg2+ at an electrical conductivity in a 1:5 soil/water extract (EC1:5) of 1 dS m-1. Water-extractable organic C was derived from wheat straw, and microbial activity after sorption was quantified by measuring CO2 emission from the soils for 27 days. The concentration of sorbed C was higher in the sandy clay loam than in the loamy sand and decreased in the treatment order Ca2+ > Mg2+ > K+ > Na+, but cumulative CO2-C emission after sorption was highest from the Na+ and lowest from the Ca2+ treatments. The strong binding in the Ca2+ and Mg2+ treatments can be explained by the low zeta potential and the high covalency index of cation binding with C, whereas zeta potential was high and the covalency index was low in the Na+ treatments. Although K+ is also monovalent, WEOC was more strongly bound in the K+ than in the Na+ treatment. The weak binding with Na increased the accessibility of the sorbed C to soil microbes and, thus, microbial activity. Our results suggest that monovalent cations may enhance decomposition and leaching of WEOC in saline soils with Na+ having a greater effect than K+. Divalent cations, particularly Ca2+, enhance the binding of organic matter and thus organic C stabilization, whereas Mg2+ ions have a smaller effect. © 2013 Springer-Verlag Berlin Heidelberg.
Kumar S.,Indian Institute of Remote Sensing |
Singh R.P.,Punjab Remote Sensing Center
Environmental Earth Sciences | Year: 2016
Terrain attributes derived from digital terrain model (DTM) were used to study spatial variation of total soil C, N and available P in surface soils of a watershed of Himalayan landscape. Terrain attributes elevation, slope gradient and upslope catchment area (UCA) and terrain indices [terrain wetness index (TWI), water power index (WPI) and sediment transport index (STI)] were derived from DTM and evaluated for their potential in soil nutrients mapping. These nutrients showed positive correlation with UCA, TWI, SPI and STP terrain indices. Among these terrain indices, TWI showed highest correlation coefficient for TC (r2 = 0.71), N (r2 = 0.67) and P (r2 = 0.66) followed by WPI and STI. Geostatistical analyses used to map these nutrients, co-kriging with TWI + NDVI, TWI and slope as co-variables, had improved the spatial prediction to 60.46, 55.81, 44.18 % for TC and 33.63, 21.78, 17.82 % for N, respectively, contrary to ordinary kriging. The prediction accuracy for P was improved with co-variables of TWI + NDVI and TWI by 30.03 and 4.50 %, respectively. The study clearly revealed that by integrating NDVI as co-variable has significantly improved the accuracy for TC followed by N and P. TWI alone as co-variable has improved the spatial prediction significantly. © 2016, Springer-Verlag Berlin Heidelberg.
PubMed | Guru Angad Dev Veterinary and Animal Sciences University, Punjab Remote Sensing Center and National Research Center on Equines
Type: | Journal: Acta tropica | Year: 2016
Equine piroplasmosis is a febrile, tick-borne disease of equids predominately caused by obligatory intra-erythrocytic protozoa Theileria equi in the Indian sub-continent. A cross-sectional study was carried out on 464 equids (426 horses and 38 donkeys/mules) in Punjab, India to assess the level of exposure to equine piroplasmosis by 18S rRNA gene nested polymerase chain reaction (nPCR) and equine merozoite antigen-2 (EMA2) indirect-ELISA (enzyme linked immunosorbent assay), to investigate risk factors and haemato-biochemical alterations associated with the infection. The endemicity of the disease was confirmed by positive PCR amplification in 21.77% and positive antibody titers in 49.78% equid samples. There was a fair agreement between these two diagnostic techniques (Kappa coefficient=0.326). The spatial distribution analysis revealed an increasing trend of T. equi prevalence from north-eastern to south-western region of Punjab by both the techniques correspondingly, which proffered a direct relation with temperature and inverse with humidity variables. The relatively prominent risk factor associated with sero-positivity was the presence of other domestic animals in the herd, while the propensity of finding a positive PCR amplification was higher in donkeys/mules, animal kept at unorganised farm or those used for commercial purposes as compared to their counterparts. There was a significant increase in globulins, gamma glutamyl-transferase, total bilirubin, direct bilirubin, indirect bilirubin, glucose levels and decrease in total erythrocyte count, haemoglobin, packed cell volume by animals, which were revealed positive by nPCR (may or may not positive by indirect-ELISA) and increase in creatinine, total bilirubin, direct bilirubin, glucose and decrease in total erythrocytes count by animals, which were revealed positive by indirect-ELISA (alone). To our knowledge, this study, for the first time, brings out a comprehensive report on the status on spatial distribution of T. equi in Punjab (India) state, thoroughly investigated by molecular and serological techniques, evaluating various environmental and demographic risk factors along with the haemato-biochemical alterations in the exposed animals.
Dhawan A.K.,Punjab Agricultural University |
Mukherjee J.,Punjab Agricultural University |
Kang G.S.,Punjab Agricultural University |
Singh H.,Punjab Remote Sensing Center
Indian Journal of Ecology | Year: 2014
In this study the fertilization unsuitability index (FUI) has been proposed for estimating soil contamination and nutrient imbalance resulting from fertilizer application at farm source. The fertilizer use data was collected directly from the selected farmers in the study area and interpolated environmental risk resulting from over fertilization was represented in spatial format using Arc GIS software. The results reported that urea was applied more than double the amount recommended for cotton and wheat cultivation where as the diammonium phosphate was applied at recommended levels in wheat and 50% above recommended dose in cotton in majority of villages in the study area. The average value of FUI was higher in cotton (527.205) in comparison to wheat (491.35) when nitrogen and phosphorus requirement of crops was met by application of urea and diammonium phosphate. Whereas the maximum FUI was reported in Muktsar district (544.52) for fertilization in wheat crop and it was reported to be 536.82 in cotton fertilization. The average soil contamination (SC) risk was higher in cotton fertilization (2.79) than in wheat fertilization (2.47) and the maximum value was reported in Muktsar district for cotton fertilization (3.11). The wheat fertilization practice in the study area threats only nitrate pollution whereas the fertilization in cotton has associated risks of both nitrate and phosphate pollution in the study area.
Kaur M.,Punjab Remote Sensing Center |
Singh S.,Punjab Remote Sensing Center |
Verma V.K.,Punjab Remote Sensing Center |
Pateriya B.,Punjab Remote Sensing Center
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives | Year: 2014
Morphometric analysis is the measurement and mathematical analysis of the landforms. The delineation of drainage system is of utmost importance in understanding hydrological system of an area, water resource management and it's planning in an effective manner. Morphometric analysis and land use change detection of two sub-watersheds namely Kukar Suha and Ratewal of district Shahid Bhagat Singh Nagar, Punjab, India was carried out for quantitative description of drainage and characterisation. The stream order, stream number, stream length, mean stream length, and other morphometric analysis like bifurcation ratio, drainage density, texture, relief ratio, ruggedness number etc. were measured. The drainage pattern of Kukar Suha and Ratewal is mainly dendritic. The agriculture and settlements came up along the drainage network causes the pattern disturbance in the watershed. The study was undertaken to spotlight the morphometric parameters, their impact on the basin and the land use land cover changes occurred over the period of time. Morphometric parameters such as linear aspect, areal aspect and relief aspect of the watershed are computed. The land use/land cover change was extracted from LISS IV Mx + Cartosat1 PAN data. ASTER data is used to prepare DEM (digital elevation model) and geographical information system (GIS) was used to evaluate various morphometric parameters in ArcGIS10 software.
Forouzangohar M.,University of Melbourne |
Setia R.,Punjab Remote Sensing Center |
Wallace D.D.,Agriculture Productivity Group |
Nitschke C.R.,University of Melbourne |
Bennett L.T.,University of Melbourne
Climate Research | Year: 2016
Research on the impacts of climate change on soil organic carbon (SOC) stocks has focused on the effects of changes in average climate, but the potential effects of increased climate variability, including more frequent extreme events, remain under-examined. In this study, set in a semiarid agricultural landscape in southeastern Australia, we used the Rothamsted carbon (RothC) model to isolate the effects of interannual rainfall variability on SOC stocks over a 50 yr period. We modelled SOC trends in response to 3 scenarios that had the same 50 yr average climate but different interannual rainfall distributions: non-changing average climate, historic variability (H), and increased variability due to more frequent extreme rainfall years (XH). Relative to the non-changing average climate, RothC simulations predicted net decreases in mean SOC stocks to 50 yr of 11% under the H scenario and 13% under the XH scenario. These decreases were the result of predicted SOC decreases (and increased CO2 emissions) in extreme wet years (ca. 0.26 Mg ha-1 yr-1) that were not counterbalanced by SOC increases in extreme dry years (ca. 0.11 Mg ha-1 yr-1). No significant difference in mean SOC stocks at 50 yr between the H and XH scenarios was likely due to an increase in both extreme wet and counterbalancing extreme dry years in the latter. Strong negative correlations were found between annual changes in SOC stocks and rainfall. Our modelled predictions indicate the potential for extreme rainfall years to influence SOC gains and losses in semiarid environments and highlight the importance of maintaining plant inputs in these environments, particularly during extreme wet years. © Inter-Research 2016.
Minakshi,Punjab Remote Sensing Center |
Verma V.K.,Punjab Remote Sensing Center
Indian Journal of Ecology | Year: 2014
In the present study of Rajni Devi sub-watershed, focus was on the drainage parameters and their impact on the land use of the basin. Satellite remote sensing and GIS have been used to map the various land use classes along with drainage parameters. Ten land use/land cover classes have been identified at level III and the stream Is of sixth order. The 0.63 value of elongation ratio in the study area showed it to be slightly elongated basin and the concentration time of flow is high, resulting deposition of the solids along the choes.
Buttar G.S.,Punjab Agricultural University |
Jalota S.K.,Punjab Agricultural University |
Sood A.,Punjab Agricultural University |
Sood A.,Punjab Remote Sensing Center |
Bhushan B.,Punjab Agricultural University
Indian Journal of Agricultural Sciences | Year: 2012
Cotton cultivation in semi-arid region of Indian Punjab is considered as most risky crop as its yield is very sensitive to weather parameters like rain and temperature. In future due to global warming increase in the temperature is expected, which is most likely to influence the growth and yield of this fiber crop like other cereal crops. Studies on the effect of temperature on the growth and seed yield of Bt cotton in this region are lacking. The present 2-year field and 15-year simulation studies concern to simulate the effect of temperature on duration of pheno-phases and seed yield of Bt cotton hybrid RCH 134 and also on crop water productivity. Simulations were run for 15 years (1991-2005) using the already customized CropSyst model. The simulated results indicated that with increase in temperature from 28 to 32oC, cotton seed yield was reduced to half (from 4 700 to 2 300 kg/ha) following a linear relation with high coefficient of determination (0.97), and the reduction was more with increased temperature during sowing to flowering stage than other pheno-phases. Total evapo-transpiration (ET) during crop period and crop water productivity was also decreased with increased temperature. Relationship of cotton seed yield was linear with ET and quadratic with total water supply (rain +irrigation). Real crop water productivity (yield/ET) and apparent crop water productivity (yield/irrigation water) were 0.362+0.129 and 0.485+0.120 kg/m 3, respectively.