The Experts below are selected from a list of 984 Experts worldwide ranked by ideXlab platform
S S Kukal - One of the best experts on this subject based on the ideXlab platform.
-
percolation losses of water in relation to pre Puddling tillage and Puddling intensity in a puddled sandy loam rice oryza sativa l field
Soil & Tillage Research, 2004Co-Authors: S S Kukal, A S SidhuAbstract:Abstract Effects of Puddling in rice ( Oryza sativa L.), especially the water loss, depend upon the extent of initial manipulation by pre-Puddling tillage. The interactive effects of pre-Puddling tillage and Puddling intensity were studied for 3 years (2000–2002) in a field experiment at Punjab Agricultural University, Ludhiana, India, on a sandy loam soil (coarse loamy, calcareous, mixed, hyperthermic Typic Ustochrept). Treatments included three levels of pre-Puddling tillage-one discing followed by a tine cultivation and planking, one discing followed by two tine cultivations and plankings and one discing followed by four tine cultivations and plankings; and three levels of Puddling-one, two and four cultivations in ponded water each followed by planking. Increasing pre-Puddling tillage intensity to four operations decreased percolation rate of water by 22–40% from that with one operation. Four Puddling operations decreased percolation rate of soils by 30% from that with one Puddling operation. This led to decrease in irrigation water used by 22–27% when pre-Puddling tillage intensity increased from one to four operations. During an irrigation cycle, the percolation rate of soils decreased with time (days 1–4 after irrigation), the extent of decrease being same at all the levels of pre-Puddling tillage. Higher levels of Puddling increased the clay content of 0–1, 1–2 and 2–3 cm soil layers, the increase being more pronounced at higher levels of pre-Puddling tillage. Puddling index, ratio of initial to final volume of settled sediments, was not affected by pre-Puddling tillage intensity. It, however, increased with increasing levels of Puddling intensity. Puddling index was also not a function of clay content of the surface soil layers (0–3 cm).
-
Puddling depth and intensity effects in rice wheat system on a sandy loam soil ii water use and crop performance
Soil & Tillage Research, 2003Co-Authors: S S Kukal, G C AggarwalAbstract:Abstract The effect of Puddling in reducing water losses and increasing rice yields is thought to be a function of its intensity. However, increased Puddling intensity may have a negative effect on yield of succeeding wheat crop due to subsoil compaction. A 3-year field experiment was conducted on a sandy loam soil (coarse loamy, calcareous, mixed, hyperthermic Typic Ustochrept) to study the effect of Puddling intensity and Puddling depth on irrigation water use in rice (Oryza sativa) and the performance of rice and wheat (Triticum aestivum) crops. The treatments on main plots included (i) no Puddling, (ii) and (iii) medium Puddling-2 passes of a tractor-drawn cultivator followed by leveling with a wooden plank and (iv) and (v) high Puddling-4 passes of a tractor-drawn cultivator followed by leveling with a wooden plank, each at shallow (5–6 cm) and normal (10–12 cm) depths. Percolation losses decreased by 14–16% with the increase in Puddling intensity from medium to high, whereas the amount of irrigation water required decreased by 10–25%. Puddling depth did not affect percolation losses or the amount of irrigation water applied. Intensive Puddling intensity resulted in higher root mass density (RMD) in 0–5 and 5–10 cm soil layers. In 0–5 cm soil layer, the RMD in the shallow-puddled plots was 17% more than in deeply puddled plots. Puddling treatments had no effect on total dry matter and grain yield of rice in any of the 3 years of study. During the third year, the RMD of wheat in the 0–15 cm depth of the deeply puddled plots was 7% larger than in shallow-puddled plots. At depths greater than 15 cm, the RMD was 11–68% less in the deeply puddled plots than in the shallow-puddled plots. RMD of wheat in the 0–15 cm soil layer increased from 302 μg cm−3 in 1994–1995 to 319 μg cm−3 in 1996–1997 whereas in the 15–30 cm layer it decreased from 85 to 47 μg cm−3. High Puddling intensity increased the canopy temperature of wheat by 0.5–1.7 °C and decreased average xylem water potential by 4–7%. During the 1996–1997 season, the total dry matter and wheat grain yield of wheat were, respectively, 19 and 8% greater in the shallow-puddled plots than the deeply puddled plots.
-
Puddling depth and intensity effects in rice wheat system on a sandy loam soil i development of subsurface compaction
Soil & Tillage Research, 2003Co-Authors: S S KukalAbstract:Abstract Puddling, even though reduces percolation losses of irrigation water in rice production, it also results in yield decline of wheat ( Triticum aestivum L.) that follows the rice crop in the cropping sequence because of subsurface compaction. The 3-year field study reported in this paper evaluates the effects of Puddling depth and intensity on the development of subsurface compaction in a sandy loam soil (coarse loamy, mixed, hyperthermic Typic Ustochrept). The treatments included two passes of tractor-drawn cultivator followed by levelling with a wooden plank (medium Puddling) and four passes of tractor-drawn cultivator followed by levelling with a wooden plank (intensive Puddling). Both medium and intensive Puddling treatments were imposed at shallow (5–6 cm) and normal (10–12 cm) depths. Increase in Puddling intensity from medium to intensive, significantly increased bulk density from 1.63 to 1.67 Mg m −3 in 16–18 cm and from 1.61 to 1.66 Mg m −3 in 18–20 cm soil layers. In normal-puddled plots, the average bulk density of 14–20 cm soil layers was significantly higher (1.74 Mg m −3 ) than that of shallow puddled plots (1.57 Mg m −3 ) at the end of 3 years of study. Similar trends were observed in case of soil penetration resistance.
-
percolation losses of water in relation to Puddling intensity and depth in a sandy loam rice oryza sativa field
Agricultural Water Management, 2002Co-Authors: S S Kukal, G C AggarwalAbstract:Abstract Percolation loss of water in rice fields is a major factor of low water use efficiency of irrigated rice thus threatening its sustainability. The process of water percolation was studied in a puddled sandy loam rice field with three Puddling intensities—no Puddling (unpuddled), two passes of tractor-drawn cultivator+one planking (medium-Puddling), and four passes of tractor-drawn cultivator+one planking (high-Puddling), each at shallow (5–6 cm) and normal (10–12 cm) depths. Percolation losses of water decreased with medium-Puddling by 54–58%, but it remained unaffected by increased Puddling intensity and Puddling depth. Percolation rate (PR) decreased with time with both medium- and high-Puddling but it increased with increased depth of ponding water. The PR of water recorded in infiltration rings was 1.8, 38.8 and 42.1% less than that recorded in the whole plots thereby indicating the role of under-bund losses. Seepage ratio (ratio of seepage plus percolation to percolation alone) increased with increase in Puddling intensity indicating that the magnitude of under-bund percolation was a direct function of Puddling intensity. The hydraulic conductivity of the puddled layer decreased with increased Puddling intensity (0.064 cm h −1 with medium-Puddling to 0.009 cm h −1 with high-Puddling) whereas the hydraulic gradient between puddled and unpuddled layers increased with increase in Puddling intensity (0.84 cm cm −1 with medium-Puddling to 1.86 cm cm −1 with high-Puddling)
G C Aggarwal - One of the best experts on this subject based on the ideXlab platform.
-
Puddling depth and intensity effects in rice wheat system on a sandy loam soil ii water use and crop performance
Soil & Tillage Research, 2003Co-Authors: S S Kukal, G C AggarwalAbstract:Abstract The effect of Puddling in reducing water losses and increasing rice yields is thought to be a function of its intensity. However, increased Puddling intensity may have a negative effect on yield of succeeding wheat crop due to subsoil compaction. A 3-year field experiment was conducted on a sandy loam soil (coarse loamy, calcareous, mixed, hyperthermic Typic Ustochrept) to study the effect of Puddling intensity and Puddling depth on irrigation water use in rice (Oryza sativa) and the performance of rice and wheat (Triticum aestivum) crops. The treatments on main plots included (i) no Puddling, (ii) and (iii) medium Puddling-2 passes of a tractor-drawn cultivator followed by leveling with a wooden plank and (iv) and (v) high Puddling-4 passes of a tractor-drawn cultivator followed by leveling with a wooden plank, each at shallow (5–6 cm) and normal (10–12 cm) depths. Percolation losses decreased by 14–16% with the increase in Puddling intensity from medium to high, whereas the amount of irrigation water required decreased by 10–25%. Puddling depth did not affect percolation losses or the amount of irrigation water applied. Intensive Puddling intensity resulted in higher root mass density (RMD) in 0–5 and 5–10 cm soil layers. In 0–5 cm soil layer, the RMD in the shallow-puddled plots was 17% more than in deeply puddled plots. Puddling treatments had no effect on total dry matter and grain yield of rice in any of the 3 years of study. During the third year, the RMD of wheat in the 0–15 cm depth of the deeply puddled plots was 7% larger than in shallow-puddled plots. At depths greater than 15 cm, the RMD was 11–68% less in the deeply puddled plots than in the shallow-puddled plots. RMD of wheat in the 0–15 cm soil layer increased from 302 μg cm−3 in 1994–1995 to 319 μg cm−3 in 1996–1997 whereas in the 15–30 cm layer it decreased from 85 to 47 μg cm−3. High Puddling intensity increased the canopy temperature of wheat by 0.5–1.7 °C and decreased average xylem water potential by 4–7%. During the 1996–1997 season, the total dry matter and wheat grain yield of wheat were, respectively, 19 and 8% greater in the shallow-puddled plots than the deeply puddled plots.
-
percolation losses of water in relation to Puddling intensity and depth in a sandy loam rice oryza sativa field
Agricultural Water Management, 2002Co-Authors: S S Kukal, G C AggarwalAbstract:Abstract Percolation loss of water in rice fields is a major factor of low water use efficiency of irrigated rice thus threatening its sustainability. The process of water percolation was studied in a puddled sandy loam rice field with three Puddling intensities—no Puddling (unpuddled), two passes of tractor-drawn cultivator+one planking (medium-Puddling), and four passes of tractor-drawn cultivator+one planking (high-Puddling), each at shallow (5–6 cm) and normal (10–12 cm) depths. Percolation losses of water decreased with medium-Puddling by 54–58%, but it remained unaffected by increased Puddling intensity and Puddling depth. Percolation rate (PR) decreased with time with both medium- and high-Puddling but it increased with increased depth of ponding water. The PR of water recorded in infiltration rings was 1.8, 38.8 and 42.1% less than that recorded in the whole plots thereby indicating the role of under-bund losses. Seepage ratio (ratio of seepage plus percolation to percolation alone) increased with increase in Puddling intensity indicating that the magnitude of under-bund percolation was a direct function of Puddling intensity. The hydraulic conductivity of the puddled layer decreased with increased Puddling intensity (0.064 cm h −1 with medium-Puddling to 0.009 cm h −1 with high-Puddling) whereas the hydraulic gradient between puddled and unpuddled layers increased with increase in Puddling intensity (0.84 cm cm −1 with medium-Puddling to 1.86 cm cm −1 with high-Puddling)
-
Puddling and n management effects on crop response in a rice wheat cropping system
Soil & Tillage Research, 1995Co-Authors: G C Aggarwal, A S Sidhu, N K Sekhon, K S Sandhu, H S SurAbstract:Abstract Coarse-textured soils are puddled to reduce high percolation losses of irrigation water under rice ( Oryza sativa L.). This practice, however, reduces yield of succeeding wheat ( Triticum aestivum L.) owing to deterioration in soil physical conditions. The 6 year field study reported in this paper evaluated the effects of Puddling level and integrated N management on the development of subsurface compaction and growth and yield of rice and the following spring wheat grown in 1 year sequence on a sandy loam soil. Treatments were combinations of three Puddling levels: low (one discing and one planking), medium (two discings and one planking), and high (four discings and one planking), and three nitrogen sources: (1) 120 kg N ha −1 from urea, (2) 60 kg N ha −1 from urea plus sesbania ( Sesbania aculeata Pers.) green manure, and (3) 60 kg N ha −1 from urea plus 20 Mg ha −1 farmyard manure. Percolation rate decreased from 14 mm day −1 with low Puddling to 10 mm day −1 with high Puddling, with a corresponding reduction in irrigation water requirement of rice of about 20%. Bulk density profiles in the 0–30 cm soil layer showed the formation of a compact layer at 15–20 cm depth, and bulk density increased with Puddling level and cropping season. The impact of organic amendments in reducing bulk density was immediate, but the rate of increase in bulk density with time was the same in all the nitrogen sources. Organic amendments did not affect percolation rate and irrigation requirement of rice. Rice yields were not significantly affected by Puddling and N source treatments throughout the study period. Residual effects of treatments on wheat yield were observed from the second season onwards. Interactive effects of Puddling and N source on yields of rice and succeeding wheat were not significant. Yield differences in wheat between high and low Puddling were 8% and 11% during the second and the fifth cropping season, respectively. This study indicates that medium Puddling was optimum, as it reduced percolation without decreasing yield of succeeding wheat.
R.p. Tripathi - One of the best experts on this subject based on the ideXlab platform.
-
influence of tillage and crop residue on soil physical properties and yields of rice and wheat under shallow water table conditions
Soil & Tillage Research, 2007Co-Authors: R.p. Tripathi, Peeyush Sharma, Surendra SinghAbstract:An experiment was conducted to evaluate the effects of tillage and residue incorporation on soil properties and yields of rice (Oryza sativa L.) and wheat (Triticum aestivum L.) in rotation for 4 years on a silty clay loam of an Aquic Hapludoll with natural water table fluctuating between 0.05 and 0.97 m depth The rice experiment was laid out in split plot design with four levels of tillage, viz. conventional Puddling (CP), Puddling by four passes of rotavator (PR), reduced Puddling by two passes of rotavator (ReP), and direct seeding without Puddling (DSWP) and two levels of residue, viz. residue incorporation (RI) and residue removal (RR) in four replications. The treatments for wheat were zero tillage (ZT) and conventional tillage (CT) with RI and RR superimposed over the plots of rice. Tillage for rice increased Puddling index and bulk density (BD) over the years. The increase was significantly higher in CP and PR than in ReP. In wheat season, BD was higher under ZT than under CT but the differences were not significant. Puddling decreased saturated hydraulic conductivity with time, which became significantly lower in CP and PR in the fourth year than in ReP in the first year. Infiltration rate (IR) also decreased with time and was lowest in CP and PR. In wheat season, IR was at par under ZT and CT. Rice yield in PR was maximum and at par with that in ReP. But wheat yield was lowest in PR and highest in DSWP, and was at par in DSWP and ReP. Thus, rice yields were optimum under ReP, in which changes in soil properties were least, and wheat yields were optimum both under ZT and CT in the DSWP and ReP plots of rice under shallow water table conditions of the silty clay loam.
-
tillage effects on soil physical properties and performance of rice wheat cropping system under shallow water table conditions of tarai northern india
European Journal of Agronomy, 2005Co-Authors: R.p. Tripathi, Peeyush Sharma, Surendra SinghAbstract:Abstract This study was conducted for 3 years in silty clay loam (Aquic hapludoll) associated with water tables fluctuating between 0.05 and 0.96 m depths from the surface. Tillage treatments for rice ( Oryza sativa L.) were Puddling by four passes of rotary puddler (PR), reduced Puddling (ReP) for two passes of rotary puddler, conventional Puddling (CP) and direct seeding without Puddling (DSWP) in four replications. Tillage treatments for wheat ( Triticum aestivum L.) were zero tillage (ZT) and conventional tillage (CT) superimposed over the plots of rice tillage treatments. Puddling caused a significant reduction in saturated hydraulic conductivity (Ks), infiltration rate (IR), and specific volume (Rv). The reduction in Ks in the PR plot at 30 days after transplanting was 27 and 46% (3-year average) higher than in the ReP and DSWP plots, respectively, but was statistically at par with that in the CP plot in the surface tilled layer. This indicates that Puddling by four passes of rotary puddler and that by conventional method adopted by farmers in those conditions gives the same level of control on percolation rate. Highest rice yield (5607 kg ha −1 ) was obtained in the PR plot, which was statistically equal to that in the ReP plot. Wheat yield was highest (4020 kg ha −1 ) in the DSWP plot of rice under CT condition. Total average grain production (rice + wheat) was highest under ReP–CT treatment combination. Results thus show that quality of soil puddle obtained by half the efforts in conventional Puddling was sufficient for a significantly high yield of rice with minimum deterioration of soil properties. Similarly, wheat sowing by conventional tillage in such a reduced Puddling plots of rice was sufficient for a significantly high yield of wheat.
-
Evaluation of non-Puddling under shallow water tables and alternative tillage methods on soil and crop parameters in a rice–wheat system in Uttar Pradesh
Soil & Tillage Research, 2000Co-Authors: R.k Bajpai, R.p. TripathiAbstract:Abstract The existence of a shallow water table (surface to 0.54 m from June to October) is common phenomenon in Tarai (foothills of the Himalaya) of Uttar Pradesh, India. Puddled rice ( Oryza sativa L.) crop followed by conventional land preparation for the succeeding wheat ( Triticum aestivum L.) crop is normal cultivation practice in the region. This shallow water table can be effectively utilised to avoid Puddling operations for the seeding of rice and reduce the degree of tillage required for the following wheat crop. An investigation was made in silty clay loam (Chernozem), for two consecutive years (1992–1993 and 1993–1994) at Pantnagar, India, in a rice–wheat cropping system. The treatments for rice were Puddling and non-Puddling with two fertility levels (NPK: 120:40:40 and 180:60:60) and for wheat two tillage systems (conventional and zero tillage) in puddled and non-puddled rice field with two fertility levels. Puddling significantly reduced the bulk density of the surface (0–0.06 m) soil at the tillering stage of rice, compared to non-Puddling, whereas it was significantly higher after harvest. The hydraulic conductivity of the 0–0.06 m soil depth also reduced to one-sixth and one-half due to Puddling at tillering and harvesting stages, respectively. Infiltration rate was decreased from 0.68 to 0.46 mm h −1 at tillering and 1.78 to 0.94 mm h −1 at harvest due to Puddling. The Puddling only in rice enhanced the root length density by 12% but affected adversely the wheat crop and minimised the root length density by 28%. Both Puddling and non-Puddling were found to be equally effective for grain yield of rice. However, non-Puddling of rice produced significantly higher wheat grain yield than that of wheat followed by puddled rice. Conventional tillage of wheat produced significantly higher (25%) grain yield than that of zero tillage. This study indicated that in shallow water table conditions, direct drilling of rice in place of puddled rice and conventional tillage for wheat is an alternative cultivation practice in a rice–wheat system.
-
long term effect of Puddling and fertilizer use in rice wheatcowpea sequence on structural properties of soil
Journal of the Indian Society of Soil Science, 1996Co-Authors: R.p. Tripathi, Nand RamAbstract:Effect of Puddling; fertilizers and manures on Puddling index, bulk density, aggregate stability, air-filled porosity and penetration resistance of soil was evaluated in a 20-year old experiment under rice-wheat-cowpea on a Hapludoll. Bulk density increased and water stable aggregate decreased as a result of Puddling. Bulk density and cone index values showed the development of a hard pan at 0.15 m depth from the surface.
Surendra Singh - One of the best experts on this subject based on the ideXlab platform.
-
influence of tillage and crop residue on soil physical properties and yields of rice and wheat under shallow water table conditions
Soil & Tillage Research, 2007Co-Authors: R.p. Tripathi, Peeyush Sharma, Surendra SinghAbstract:An experiment was conducted to evaluate the effects of tillage and residue incorporation on soil properties and yields of rice (Oryza sativa L.) and wheat (Triticum aestivum L.) in rotation for 4 years on a silty clay loam of an Aquic Hapludoll with natural water table fluctuating between 0.05 and 0.97 m depth The rice experiment was laid out in split plot design with four levels of tillage, viz. conventional Puddling (CP), Puddling by four passes of rotavator (PR), reduced Puddling by two passes of rotavator (ReP), and direct seeding without Puddling (DSWP) and two levels of residue, viz. residue incorporation (RI) and residue removal (RR) in four replications. The treatments for wheat were zero tillage (ZT) and conventional tillage (CT) with RI and RR superimposed over the plots of rice. Tillage for rice increased Puddling index and bulk density (BD) over the years. The increase was significantly higher in CP and PR than in ReP. In wheat season, BD was higher under ZT than under CT but the differences were not significant. Puddling decreased saturated hydraulic conductivity with time, which became significantly lower in CP and PR in the fourth year than in ReP in the first year. Infiltration rate (IR) also decreased with time and was lowest in CP and PR. In wheat season, IR was at par under ZT and CT. Rice yield in PR was maximum and at par with that in ReP. But wheat yield was lowest in PR and highest in DSWP, and was at par in DSWP and ReP. Thus, rice yields were optimum under ReP, in which changes in soil properties were least, and wheat yields were optimum both under ZT and CT in the DSWP and ReP plots of rice under shallow water table conditions of the silty clay loam.
-
tillage effects on soil physical properties and performance of rice wheat cropping system under shallow water table conditions of tarai northern india
European Journal of Agronomy, 2005Co-Authors: R.p. Tripathi, Peeyush Sharma, Surendra SinghAbstract:Abstract This study was conducted for 3 years in silty clay loam (Aquic hapludoll) associated with water tables fluctuating between 0.05 and 0.96 m depths from the surface. Tillage treatments for rice ( Oryza sativa L.) were Puddling by four passes of rotary puddler (PR), reduced Puddling (ReP) for two passes of rotary puddler, conventional Puddling (CP) and direct seeding without Puddling (DSWP) in four replications. Tillage treatments for wheat ( Triticum aestivum L.) were zero tillage (ZT) and conventional tillage (CT) superimposed over the plots of rice tillage treatments. Puddling caused a significant reduction in saturated hydraulic conductivity (Ks), infiltration rate (IR), and specific volume (Rv). The reduction in Ks in the PR plot at 30 days after transplanting was 27 and 46% (3-year average) higher than in the ReP and DSWP plots, respectively, but was statistically at par with that in the CP plot in the surface tilled layer. This indicates that Puddling by four passes of rotary puddler and that by conventional method adopted by farmers in those conditions gives the same level of control on percolation rate. Highest rice yield (5607 kg ha −1 ) was obtained in the PR plot, which was statistically equal to that in the ReP plot. Wheat yield was highest (4020 kg ha −1 ) in the DSWP plot of rice under CT condition. Total average grain production (rice + wheat) was highest under ReP–CT treatment combination. Results thus show that quality of soil puddle obtained by half the efforts in conventional Puddling was sufficient for a significantly high yield of rice with minimum deterioration of soil properties. Similarly, wheat sowing by conventional tillage in such a reduced Puddling plots of rice was sufficient for a significantly high yield of wheat.
Xinhua Peng - One of the best experts on this subject based on the ideXlab platform.
-
impact of soil Puddling intensity on the root system architecture of rice oryza sativa l seedlings
Soil & Tillage Research, 2019Co-Authors: Huan Fang, Hu Zhou, Hui Rong, Paul D Hallett, Sacha J Mooney, Weijian Zhang, Xinhua PengAbstract:Abstract Puddling of rice paddies is undertaken to create a soft soil bed for easy transplanting of rice seedlings, to control weeds and reduce water and nutrient leaching. There is a drive for less intense Puddling because of its physical disturbance of soil, energy inputs and labour requirements, which may produce different soil physical conditions for root growth. The objective of this study was to investigate the influence of Puddling intensity on soil structure and the subsequent impact on the growth of rice seedling roots. Three treatments with different Puddling intensities were established: (1) No Puddling; (2) Low and (3) High intensity Puddling. The rice genotype, Nipponbare was grown in soil columns for 18 days. Soil bulk density, aggregate size distribution and three-dimensional (3D) macropore structure were measured. Two-dimensional root traits were determined by WinRhizo and 3D root traits were determined by X-ray Computed Tomography (CT). Our results show the percentage of large macroaggregates (> 2 mm) decreased by 69.6% (P 0.03 mm) of no Puddling was 2.3 times greater than low intensity Puddling and 3.5 times greater than high intensity Puddling. The total root lengths of no and low intensity Puddling were 1.56–1.86 times greater than that of high intensity Puddling. Large roots, including radicle and crown roots, were the same length regardless of Puddling intensity. Our study demonstrates that intensive Puddling can degrade soil structure, which consequently limits rice root growth.
-
Puddling intensity sesquioxides and soil organic carbon impacts on crack patterns of two paddy soils
Geoderma, 2016Co-Authors: Z B Zhang, H Zhou, Hangsheng Lin, Xinhua PengAbstract:Abstract Paddy soils subjected to Puddling are easily cracked under wetting and drying cycles. This phenomenon has implications for water loss and chemical leaching in paddy fields. We hypothesized that crack patterns in such paddy soils result from aggregate size distribution created by Puddling under submerged condition. Soil organic carbon (SOC) and sesquioxides are main binding agents of aggregation while Puddling is a disruptive force of aggregates. In this study, our aim was to investigate the effects of Puddling intensity, SOC, and sesquioxides on cracking in two paddy soils — one cultivated for 20 years (YPF soil) and the other cultivated for over 100 years (OPF soil). The Puddling intensity was simulated by ultrasonic dispersion at applied energy of 0–800 J ml− 1. The soils were treated chemically by water as a control as well as by oxalate, dithionite-citrate-bicarbonate (DCB), or by H2O2. The aggregate size distribution and crack patterns were determined after the simulated Puddling and the chemical treatments. The results showed that the simulated Puddling and the chemical treatments increased clay- (
-
effects of simulated Puddling intensity and pre drying on shrinkage capacity of a paddy soil under long term fertilization
Soil & Tillage Research, 2014Co-Authors: Chao Deng, Xinhua Peng, Xiaolong Teng, Bin ZhangAbstract:Abstract Soil structure in paddy fields is affected by different practices such as long-term fertilization and temporal Puddling and drying. However, their interactive effects remain unclear. The objectives of this study were to determine the effects of long-term fertilization on soil structural stability at different Puddling intensities and to determine the effects of Puddling intensity and pre-drying on shrinkage behavior upon drying. Soil samples were taken from long-term experiments established in 1981 and Puddling intensity was simulated by mixing soil in water at different speeds using an electronic mixer. Compared with no fertilization and chemical fertilization treatments, the organic amendment treatments had higher soil organic carbon concentration, and larger aggregate stability under the low and moderate Puddling intensities. The shrinkage capacity (COLE) of the puddled soils ranging from 0.124 to 0.229 was larger in the organic amendment treatments than in other treatments without pre-drying. The difference in COLE among the treatments diminished with increasing Puddling intensity and after the pre-drying. The shrinkage curves and their fitted parameters demonstrated that the larger shrinkage capacity in the organic amendment treatments resulted from the increases in the macro- and meso-pores due to the presence of more large size aggregates after Puddling. The macro-pores were lost after the intensive Puddling and the meso-pores collapsed after the pre-drying at the proportional shrinkage stage, resulting in no differences in the shrinkage curve among the field treatments. These results suggest that continuous organic amendment may be needed to maintain a porous structure of paddy soil through the increase in resistance to Puddling and its influence on the shrinkage capacity upon drying.
