Sandy Regosol Research Articles

Yield Response of Abelmoschus Esculentus as Influenced by Compost With Tithonia Leaves

Tithonia diversifolia is a genus of flowering plants and its leaves have been used to improve fertility and soil properties by supplying organic matters and nutrients. This experiment was done to study the effect of compost with powdered Tithonia leaves on okra yield and to select the optimal quantity of Tithonia leaves for obtaining the optimum yield of okra in the sandy regosol soil conditions. This experiment was carried out in a completely randomized design with five replicates with the following treatments; T1 - recommended chemical fertilizers (control), T2 - compost 140 g alone, T3 - compost 140 g + 15 g powdered Tithonia leaves (PTL), T4 - compost 140 g + 30 g PTL, T5 - compost 140 g + 45 g PTL, T6 - compost 140 g + 60 g PTL. These fertilizers were applied as the basal application to each polybag (0.07 m2), while the top dressing was not applied in this experiment. The results revealed that compost with PTL application had effects on the number of pods per plant, the number of seeds per pod, pod length, pod girth, single pod weight, fresh pod weight per plant and marketable pod yield. Further, it was found that T4 was more suitable for obtaining a better marketable pod yield of okra in sandy regosol soil conditions. Based on the results obtained, it can be concluded that 2 kg m-2 compost with 0.43 kg m-2 powdered Tithonia leaves as the basal application could be used in okra cultivation.

The effect of biochar on mycorrhizal fungi mediated nutrient uptake by coconut (Cocos nucifera L.) seedlings grown on a Sandy Regosol

Biochar amendment of soil may ameliorate inherently infertile soils, such as in the typical coconut (Cocos nucifera L.) growth areas along tropical coasts, where, moreover, temporary moisture stress commonly occurs. We conducted a pot experiment to evaluate the effects of biochar soil amendment (1% w/w) produced from Gliricidia sepium stems (BC-Gly) and rice husks (BC-RiH) on the growth of coconut seedlings and on N and P uptake mediated by mycorrhizae under wet or dry conditions in a Sandy Regosol. The pots were divided into root and hyphal zones by a nylon mesh, where 15N labelled N and P nutrients were only provided in the hyphal zone. Under wet conditions, biochar application did not affect plant growth, while under dry conditions, the BC-Gly increased root and plant growth similar to that under wet conditions. BC-Gly increased the acidic pH of the soil to a neutral level, and the microbial community shifted towards a higher fungal abundance. The P accumulated (Pacc) in roots was higher with BC-Gly and BC-RiH under dry and wet conditions, respectively. Pacc weakly correlated with the abundance of arbuscular mycorrhizal fungi (AMF) in the hyphal zone. With BC-Gly roots showed lower N derived from fertilizer. We conclude that biochar application has no impact on crop growth under wet conditions, while under dry conditions, BC-Gly stimulates crop growth and P uptake, probably through liming induced P availability but also possibly by some enhancement of AMF growth. The shift in the fungal-oriented microbial community and reduced plant fertilizer N uptake suggested that BC-Gly acted as an additional N source.Graphical

Impact of Hydrogels on Early Growth of Maize in Sandy Regosols: Progress towards Improving Growth Performance by Enhancing Water and Nutrients Retention Capacity of the Soil

Super Absorbent Polymers or hydrogels are known for enhancing the water-holding properties of soils. This experiment was conducted to evaluate the influence of four different locally-produced hydrogels and one commercially available hydrogel on the early growth of maize in sandy Regosols. Maize variety, Pacific 984 was tested with six treatments in Randomized Complete Block Design. T1 - Reference hydrogel (Sodium polyacrylate-based), T2 - Acrylic acid and acrylamide-based hydrogel where urea has incorporated chemically up to 11.08% (g/g), T3 - without urea incorporating to the hydrogel used in T2, T4 - similar to T2, but urea incorporated only up to 6.17% (g/g), T5- agriculture grade commercial hydrogel (Potassium polyacrylate-based) and T6 - control (without hydrogel) were used for the study. Soil properties and plant growth parameters were quantified. A significant difference was observed in soil pH, total N and available P among treatments after one month of application. Treatment 2 showed the highest total N (0.19%) while T4 showed the highest P (18.94 ppm). The highest growth performances were given by locally produced hydrogels over commercial hydrogel and control treatments. Treatment 2 recorded the highest leaf area (1153.3 cm2/plant), plant height (128.90 cm) and total dry mass production (49.36 g/plant) while T4 has recorded the highest stem girth (4.87 cm). It was observed that locally produced hydrogels including the hydrogel without incorporating urea, have given superior performance over commercial hydrogels. Therefore, it can be concluded that locally produced hydrogel-formulations can enhance the growth of maize effectively than imported commercial hydrogels.

Best tillage practices for early-growth of clonal eucalyptus in soils with distinct granulometry, drainage and profile depth

Soil tillage influences early-growth, uniformity, and productivity of commercial forests. Best tillage practices for soils with constraints of compaction, drainage or shallow soils, all reducing the effective rooting-depth, are widely unknown for subtropical forest plantations in South America. The study aimed to quantify the effects of different tillage methods on breaking up and/or turning over the soil and on physical properties in three different soils, and relationships with early growth (up to 24 months of age) of clonal Eucalyptus saligna in southern Brazil. The tillage methods consisted of subsoiling to 50 cm plus rototilling, subsoiling to 50 cm plus ridging, and subsoiling to 70 cm plus rototilling. The soils were low-drainage Planosol, shallow sandy Regosol, and compacted clayey well-drained Nitisol. The dendrometric evaluations for initial growth show the best tillage method depended on soil type and dendrometric variable. Tree height is maximized by deep subsoiling (70 cm) in Nitisol, and by shallow subsoiling (50 cm) plus ridging in Regosol and Planosol. Tree diameter at breast height and basal area were maximized by shallow subsoiling with or without ridging in Planosol, deep subsoiling in Nitisol, and shallow subsoiling with ridging or with deep subsoiling in Regosol. When considering all the studied dendometric variables (tree height, diameter at breast height, and basal area), subsoiling plus ridging is recommend for low-drainage or shallow soils, whereas deep-subsoiling is necessary in clay soils.

Effect of Different Fruit Peel Powders as Natural Fertilizers on Growth of Okra (<em>Abelmoschus esculentus</em> L.)

Purpose : Fruit peels waste is one of the waste accumulate in huge quantity every day. It is a serious problem and need to be managed to make environment free from pollution. Fruit peels are very rich in macro and micro nutrients that are beneficial for plant growth. By using fruit peel as fertilizer we can reduce load of wastes and can get more benefits than inorganic fertilizer. Research Method : The experiment was carried out in a Completely Randomized Design with six treatments having twenty replicates. Treatments were, recommended fertilizer application at basal and topdressing (T1, control), half dose of recommended fertilizer application at basal and topdressing times with 1g of banana peel powder (T2), 1g of pomegranate peel powder (T3), 1g of orange peel powder (T4), 0.5g each of banana and pomegranate peel powders (T5) and 0.5g each of orange and banana peel powders (T6) at both times. All agronomic practices were followed as per Department of Agriculture, Sri Lanka except fertilizers. Findings : The results reveals that application of fruit peel powder at basal and top dressing had significant differences (P<0.05) on plant height, number of leaves per plant, leaf area, chlorophyll content, days to 50% and 100% flowering, dry weights of leaves, stem, root and fruit, fruit length and girth. At 1st, 2nd, 3rd and 4th picking, and the highest value was obtained in T6 and lowest value in T1. Originality/ Value : Application of fruit peel powder into the soil leads to improve growth and yield of okra in sandy regosol compared to recommended inorganic fertilizer and present study suggested that, among the all tested treatments, half recommended fertilizer application at basal and topdressing times with 0.5g each of orange and banana peel powders at both times would be the most suitable fruit peel powders to get higher growth and yield of okra in sandy regosol.

Spatial Arrangements on Growth and Yield of Cowpea (<em>Vigna unguiculata L. Walp.</em>) in Intercropping

This experiment was conducted at the Crop Farm of Eastern University, Sri Lanka to evaluate the effect of different spatial arrangements on growth and yield of cowpea (Vigna unguiculata L. Walp) under okra (Abelmoschus esculentus L.) cowpea intercropping in sandy regosol. The experiment was laid out in a Randomized Complete Block Design (RCBD) having monocropping and different intercropping patterns. The results revealed that there was a significant difference (P<0.05) among treatments for plant height, root length, leaf area, leaf area index, pod length, number of total and effective nodules per plant, dry weight of effective nodules and total pod yield of cowpea. However, seeds per pod was not significantly different (P>0.05) with different plating patterns. The study concluded that 60 cm between two rows with 150 cm between two pairs of rows of okra with three rows of cowpea in between paired rows would be the most suitable planting system to get maximum growth and yield of cowpea.

Farmer Perception, Environmental Awareness, and Overuse of Fertilizer in Kalpitiya: A Preliminary Investigation using Bayesian Econometrics

Overuse of fertilizer has long been identified as a major issue in many parts of the world, including Sri Lanka. Sandy regosol soil and the shallow groundwater table in Kalpitiya, has aggravated the impacts of extensive fertigation, raising doubts on the long-term socioeconomic and environmental sustainability of intensive agricultural systems of the region. In this background, this study attempts to determine the driving factors influencing the overuse of fertilizer within the farming community in Kalpitiya. Primary data collected from face-toface interviews with 107 farmers from Kalpitya area using a pre-tested questionnaire was used to estimate a Bayesian probit model with sufficiently diffuse normally distributed priors. The model was estimated using a Random Walk Metropolis-Hastings sampling method, which iterated 125,000 times and 25,000 were discarded as burn-in. Results reveal that farmers who perceive that fertilizer has no effect on soil and groundwater tend to move away from fertilizer recommendations and are overusing. Farmers who are aware and believe that ground water is contaminated in the area tend to apply the recommended amount of fertilizer. In addition, larger farmers seem to apply recommended dosages than smaller farmers. Raising awareness through proper extension services and creating economic disutility by increased fertilizer costs coupled with the introduction of organic fertilizer could be recommended to circumvent the ill effects of overuse of fertilizer.

Effect of Soil Moisture Content and Rate of Potassium Fertilizer on Soil Potassium Content and Growth of Cowpea (Vigna unguiculata l.) Grown in Sandy Regosol in Sri Lanka

A research study was conducted to identify the effect of potassium rate and drought stress on the post-harvest soil potassium content and growth parameters of cowpea (Vigna unguiculata L.). The experiment was arranged in a Completely Randomized Design (CRD) in a factorial manner with 8 treatments (4 different rates of fertilizer potassium as muriate of potash (MOP (i) 100% of recommended level (75 kgha-1), (ii) 125% of recommended level (93.75.kgha-1), (iii) 150% of recommended level (112.5 kgha-1), and (iv) 175% of recommended level (131.25.kgha-1) at 2 different soil moisture conditions as 25% depletion and 75% depletion of available soil moisture as optimal and sub-optimal moisture condition respectively and was replicated 3 times. The post-harvest soil potassium content, chlorophyll content of leaves and cowpea growth parameters such as, dry weight of root and dry weight of shoot were recorded at vegetative and harvesting stages. The results reveal that there was a significant influence (p<0.05) of potassium rate and soil moisture on the growth parameters, leaf chlorophyll content and available soil potassium content after harvest. In overall terms potassium promoted growth of cowpea when subject to sub-optimal soil moisture. Further, it was found that the increased application of potassium fertilizer up to 175% of recommended level can be considered as a significant factor in overcoming soil moisture stress in cowpea.

Effect of Foliar Application of Banana Pseudostem Sap on Yield of Cowpea (&lt;i&gt;Vigna unguiculata&lt;/i&gt; L. Walp.) &amp;nbsp;

Improved soil fertility is a requirement for enhanced crop production. Combination of inorganic and organic fertilizers improve crop productivity while reduce environmental degradation. An experiment was carried out at Eastern University, Sri Lanka to study the effect of Foliar Application of Banana Pseudostem Sap on Yield of Cowpea (Vigna unguiculata L. Walp.) in sandy regosol. The experiment was laid out in Randomized Complete Block Design having five treatments viz; recommended inorganic fertilizer N, P, K as basal and N as topdressing (T1), N, P, 1⁄2 K as basal with recommended N as topdressing and foliar spray of 1% , 3%, 5% and 7% banana pseudostem sap solution (T2-T5) at 3rd, 5th, 7th and 9th week after planting. The results revealed that significant difference (P&lt;0.05) were noted on number of pods per plant at 1st and 2nd picking. Higher number of pods per plant, maximum pod length and girth were in T2 while low in T1. Sun dried weights of pods and number of seeds per pod were significantly (P&lt;0.05) varied at each picking. Further, cowpea yield at each picking were higher in T2 compared to tested treatments. The present study suggested that, among the tested treatments N, P, 1⁄2 K as basal with recommended N as topdressing and foliar spray of 1% Pseudostem sap solution at 3rd, 5th, 7th and 9th WAP would be the most suitable for cowpea production in sandy regosol.

Effect of Foliar Application of Banana Pseudostem Sap on Yield of Cowpea (&lt;i&gt;Vigna unguiculata&lt;/i&gt; L. Walp.) &amp;nbsp;

Improved soil fertility is a requirement for enhanced crop production. Combination of inorganic and organic fertilizers improve crop productivity while reduce environmental degradation. An experiment was carried out at Eastern University, Sri Lanka to study the effect of Foliar Application of Banana Pseudostem Sap on Yield of Cowpea (Vigna unguiculata L. Walp.) in sandy regosol. The experiment was laid out in Randomized Complete Block Design having five treatments viz; recommended inorganic fertilizer N, P, K as basal and N as topdressing (T1), N, P, 1⁄2 K as basal with recommended N as topdressing and foliar spray of 1% , 3%, 5% and 7% banana pseudostem sap solution (T2-T5) at 3rd, 5th, 7th and 9th week after planting. The results revealed that significant difference (P&lt;0.05) were noted on number of pods per plant at 1st and 2nd picking. Higher number of pods per plant, maximum pod length and girth were in T2 while low in T1. Sun dried weights of pods and number of seeds per pod were significantly (P&lt;0.05) varied at each picking. Further, cowpea yield at each picking were higher in T2 compared to tested treatments. The present study suggested that, among the tested treatments N, P, 1⁄2 K as basal with recommended N as topdressing and foliar spray of 1% Pseudostem sap solution at 3rd, 5th, 7th and 9th WAP would be the most suitable for cowpea production in sandy regosol.

Growth and Dry Matter Accumulation of Okra (&lt;i&gt;Abelmoschus esculentus&lt;/i&gt; L.) as Influenced by Different Plating Pattern Under Okra - Cowpea (&lt;i&gt;Vigna unguiculata&lt;/i&gt; L.) Intercropping

Compared to sole cropping, intercropping systems can more efficiently use the existing resources which ultimately lead to improved plant growth and dry matter accumulation. So, most of the farmers in developing countries can follow the intercropping systems with high yielding crop combinations. The experiment was carried out at the Crop Farm of Eastern University, Sri Lanka in 2018 to investigate the growth and dry matter accumulation in okra (Abelmoschus esculentus L.) as influenced by different planting patterns under okra-cowpea (Vigna unguiculata L. Walp) intercropping in sandy regosol. The experiment was laid out in a Randomized Complete Block Design (RCBD). Treatments were okra as a sole crop (T1), cowpea as a sole crop (T2), alternative planting of okra and cowpea (T3), 60/150 cm paired row planting of okra with two rows and three rows of cowpea in between paired rows (T4 and T5) and 75/120 cm paired row planting of okra with two rows and three rows of cowpea in between paired rows (T6 and T7). Plant height, root length, fresh and dry weights of plant, leaf area, leaf area index, canopy width and cumulative yield of okra were higher in T5, while chlorophyll content showed no significant difference (P&gt;0.05) with different planting patterns. The present study concluded that 60/150 cm paired row planting of okra with three rows of cowpea in between paired rows (T5) would be the most suitable planting system in sandy regosol to achieve better growth and dry matter in okra.

Selection of Best Combination of Nutrient Sources for Efficient Utilization of Nitrogen in Sandy Regosols

Selection of Best Combination of Nutrient Sources for Efficient Utilization of Nitrogen in Sandy Regosols

Yield and yield components of Arachis hypogaea L. as influenced by NPK chemical fertilizers, farm yard manure and gypsum

Field trials were conducted to evaluate the effect of chemical fertilizers, farmyard manure (FYM) and gypsum on yield and yield components of groundnut (Arachis hypogea L.). There were nine treatments included unfertilized treatment and full doses of recommended NPK fertilizers (65:100:75 kg/ha) or reduced doses of recommended NPK fertilizers (30:50:37.5 kg/ha) and FYM@10 t/ha in combination with different levels (0, 150, 300 and 450 kg/ha) of gypsum. The results exhibited that full dose of NPK fertilizers with 300 kg/ha gypsum treatment gave significantly (P&lt;0.05) higher seed yield (2777.28 kg/ha) than the full dose of NPK fertilizers alone (typical control) which had 2276.05 kg/ha. On the other hand, application of reduced dose of NPK fertilizers + 10 t/ha FYM with 450 kg/ha gypsum resulted 2609.88 kg/ha seed yield followed by 300 kg/ha gypsum application which had 2521.98 kg/ha and both values were statistically similar. Thus, use of 300 kg/ha gypsum could give high seed yield of groundnut with full dose of NPK fertilizers alone or reduced dose of NPK fertilizers and 10 t/ha FYM. However, combined application of organic and inorganic fertilizers is better practice especially on sandy regosol when considering human and soil health.Bangladesh J. Sci. Ind. Res. 51(4), 285-290, 2016

Effect of Different Doses of NK Chemical Fertilizers and Compost on Growth and Yield Attributes of Tomato (Lycopersicon esculentum Mill.)

This study was conducted to evaluate the effect of NK chemical fertilizers in combination with compost on the growth and yield attributes of tomato (Lycopersicon esculentum Mill.). The pot experiment was done in a complete randomized block design possessing eight treatments with four replicates. Fruit weight, pulp weight, seed weight, total soluble solid, leaf area and dry weights of plat parts were taken and fruit yield was calculated. All the collected data were subjected to statistical analysis. The results revealed that there were significant differences in fruit and seed weights, total soluble solid, pulp weight, 100 seed weight, pulp consistency, leaf area and crop residue. In these parameters, higher mean values were recorded in chemical fertilizers (7.5 g N + 6 g K2O + 15 g P2O5 per m2) with compost (2 kg per m2) than those in the chemical fertilizers applied alone (9.0 g N + 8 g K2O + 15 g P2O5 per m2as standard control). Total soluble solid and fruit yield were 5.73 obrix and 3.21 kg/m2 respectively in the chemical fertilizers with compost (7.5 g N + 6 g K2O + 15 g P2O5 +2 kg compost per m2) treated plants and these were statically on par with the standard control which gave 4.36 obrix total soluble solid and 3.05 kg/m2 fruit yield. The result could be concluded that application of chemical fertilizers (7.5 g N + 6 g K2O + 15 g P2O5 per m2) with compost (2 kg per m2) could increase the total soluble solid and fruit yield as well as reduce the usage of chemical fertilizers in tomato cultivation over the standard control in sandy regosol.

Occurrence and distribution of water repellency in size fractionated coastal dune sand in Sri Lanka under Casuarina shelterbelt

The occurrence of water repellency in Sri Lankan soils has not been extensively studied and reported so far. Although most Sri Lankan soils are readily wettable, some soils show water repellent conditions. In this study, we examined a dune sand under Casuarina equisetifolia shelterbelt in Sri Lanka. The objectives were to ascertain the occurrence and the distribution of water repellency along the particle size fractions and to perceive the role of intermixed organic material in producing water repellency. The soil type is locally known to be sandy Regosols (USDA classification: Ustic Quartzipsamments). Bulk soil samples were taken from 0–5, 5–10, and 10–15 cm depths. Soil samples were separated into six size fractions by passing through a set of sieves and further separated into two sets as washed (with water) and untreated. Soil organic matter (SOM) content and the water repellency were discretely determined in untreated and washed samples. Water drop penetration time (WDPT) test and modified sessile drop method were used to estimate the water repellency. Despite the low SOM content (<2%), water repellency was extreme (contact angle >118°; WDPT >3600 s) on the topmost layer (0–5 cm) and decreased with increasing soil depth. All the size fractions of the topmost layer showed significantly high repellency compared with those of the other two layers. Both the water repellency and the SOM content showed the highest values in the finest fraction and the lowest in the coarsest fraction. Washing samples with water decreased the WDPT in >96% of all size fractions in the 0–5 cm layer, and by lower proportions in the lower layers. Washing samples significantly decreased the contact angle of most size fractions although the decline did not exceed 15%. Washing with water removed a considerable portion of organic material. Despite the obvious declining through washing, both the SOM content and the water repellency showed the highest values in the smallest particle size fraction. Water repellency in both washed and untreated samples showed a considerably strong positive linear correlation with the SOM content suggesting that water-insoluble hydrophobic organic coatings might not be the dominant factor triggering water repellency in the tested sandy soils.

Improving Nutrient and Water-Holding Capacity in Sandy Regosol by Applying Locally Available Amendments

A pot experiment was carried out at the agronomy farm Eastern University, Chenkalady, Batticaloa, to study the impact of locally available organic manures on the nutrient and water holding capacity of sandy regosol. Three organic sources integrated with different rates of recommended chemical fertilizer and were evaluated with sole recommended chemical fertilizer. Twelve treatments including integrated organic manures with chemical fertilizers at different rates, sole organic manure treatment, sole chemical fertilizer treatment at recommended level and at half the recommended level and no fertilizer control. Completely Randomized Design with 3 replicates was used as layout. Soil analysis for available soil nitrogen content, moisture retention, cation exchange capacity and organic matter content were carried out at planting (red onion), just before top dressing and at the time of harvest. Integration of organic manure with chemical fertilizer favorably influenced nitrogen availability in soil. Among the organic manures poultry manure had the greatest influence on soil available nitrogen : content. Organic manures increased the soil moisture retention capacity, with tank silt (Organic deposit in dry mud) ranking first. Soil cation exchange capacity was favorably influenced by organic manure application. Cation exchange capacity was higher in tank silt treatment than other organic sources. Cation exchange capacily was increased from planting stage to just before top dressing and decreased at harvest stage. The soil organic matter content also followed a similar trend. AGRIEAST 2009 (8) p.30-38

Effect of paddy straw enrichments on nitrogen availability in sandy regosol

Effect of paddy straw enrichments on nitrogen availability in sandy regosol

Seasonal variation of leaching of nitrate under onion cultivation in sandy regosols uncl its predictions by LEACHM-N

Seasonal variation of leaching of nitrate under onion cultivation in sandy regosols uncl its predictions by LEACHM-N

Effect of cow and poultry manures as basal fertilizers on marketable fruit yield of okra (Abelmoschus esculentus l)

An experiment was conducted to study the influence of cow and poultry manures on the marketable yield of okra (Abelmoschus esculentus L) on sandy regosol. The treatments included basal applications of inorganic fertilizer (control) and combined use (10t/ha) of cow plus poultry manures (CM: PM) at ratios of 5:0, 4:1, 3:2, 2:3, 1:4 and 0:5. Significantly higher Tropical Agricultural Research and Extension 16(1): 2013: page 31-33

Impact of animal manure EM-bokashi on seed yield and quality of vegetable cowpea (Vigna unguiculata L.)

The study was undertaken to investigate the effect of EM treated animal manures (named as animal manure EM-bokashi) on yield and nutritional composition of seeds of vegetable cowpea (Vigna unguiculata L.). This experiment was carried out with five treatments and 15 replications. The pots were arranged in a completely randomized way in the net house. The treatments included a non-fertilizer application as a control, the recommended chemical fertilizer dose and three types of animal manure EM-bokashi (cattle manure EM-bokashi, goat manure EM-bokashi and poultry manure EM-bokashi). The results showed that application of EM treated animal manures significantly increased the number of leaves caused greater nodulation, produced higher number of pods per plant, yielded maximum number of seeds per pod, greater 100 seed weight, higher yield and increased seed quality compared to chemical and non-fertilizer treatments. Among the different types of animal manure EM-bokashi, goat manure EM-bokashi applied plants produced comparatively higher seed yield with good nutritional value in the present study thus it is most suitable for obtaining higher economic yield and better seed quality of vegetable cowpea on sandy regosol. DOI: http://dx.doi.org/10.3329/bjsir.v48i1.15411 Bangladesh J. Sci. Ind. Res. 48(1), 33-38, 2013