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This research was conducted to investigate the compaction performance and mechanical strength of compacted urea fertilizer in unlubricated and lubricated die systems. The ground urea 46% N fertilizer was compacted in a 13 mm flat-face cylindrical die set in both unlubricated and lubricated die systems with vegetable fatty acids and magnesium stearate as lubricants at various compaction stresses to produce urea fertilizer tablets. In conclusion, a lubricated die system reduces the frictional effects during the production of urea fertilizer tablets and also produces a mechanically stronger urea fertilizer tablet than those produced in an unlubricated die system. In addition, the vegetable fatty acids and magnesium stearate lubricants are found to improve the compaction performance of urea fertilizer tablet as well as its mechanical strength.

This research was conducted to investigate the compaction performance and mechanical strength of compacted urea fertilizer in unlubricated and lubricated die systems. The ground urea 46% N fertilizer was compacted in a 13 mm flat-face cylindrical die set in both unlubricated and lubricated die systems with vegetable fatty acids and magnesium stearate as lubricants at various compaction stresses to produce urea fertilizer tablets. In conclusion, a lubricated die system reduces the frictional effects during the production of urea fertilizer tablets and also produces a mechanically stronger urea fertilizer tablet than those produced in an unlubricated die system. In addition, the vegetable fatty acids and magnesium stearate lubricants are found to improve the compaction performance of urea fertilizer tablet as well as its mechanical strength.

Rubber seedlings raised in the soil-polybag system experience root coiling and restriction and the overhead sprinkler results in much water wastage. The objective of the study was to determine the influence of root trainers and three irrigation systems on rubber seedlings grown in a peat-based medium. The irrigation systems were the overhead sprinkler (SPR), drip (DRP) and capillary wick (WCK). The fourth treatment was the control (CTRL), which required growing rubber seedlings in conventional soil-polybags that were then irrigated using the wick system. The treatments were compared with one another in terms of their influence on nutrient loss, crop water productivity and water use efficiency, plant growth parameters and plant nutrient content of the rubber seedlings. A field experiment was carried out in a rain shelter for eight months, and data collection was carried out once per month. The experimental layout was the completely randomised block design. The results showed that WCK had the lowest cumulative leachate volume and the least cumulative nutrients leached. Both DRP and WCK had the highest plant growth parameters such as total fresh and dry weight, total leaf area and girth size, water productivity and leaf nutrient content. WCK was the best irrigation system together with the peat-based growing medium for raising rubber nursery seedlings.

Rubber seedlings raised in the soil-polybag system experience root coiling and restriction and the overhead sprinkler results in much water wastage. The objective of the study was to determine the influence of root trainers and three irrigation systems on rubber seedlings grown in a peat-based medium. The irrigation systems were the overhead sprinkler (SPR), drip (DRP) and capillary wick (WCK). The fourth treatment was the control (CTRL), which required growing rubber seedlings in conventional soil-polybags that were then irrigated using the wick system. The treatments were compared with one another in terms of their influence on nutrient loss, crop water productivity and water use efficiency, plant growth parameters and plant nutrient content of the rubber seedlings. A field experiment was carried out in a rain shelter for eight months, and data collection was carried out once per month. The experimental layout was the completely randomised block design. The results showed that WCK had the lowest cumulative leachate volume and the least cumulative nutrients leached. Both DRP and WCK had the highest plant growth parameters such as total fresh and dry weight, total leaf area and girth size, water productivity and leaf nutrient content. WCK was the best irrigation system together with the peat-based growing medium for raising rubber nursery seedlings.

Silt pit is one of the recommended soil water conservation practices in oil palm plantations. It is commonly regarded that the larger and deeper the silt pit, the more effective the pit would be to conserve soil water. This hypothesis was tested in this paper, where the effectiveness of four silt pit dimensions on conserving soil water in the oil palm active rooting zone was simulated using the HYDRUS 2D model. These silt pits had different sizes and total wet wall-to-floor area ratio (W:F): H1 silt pit (1x1x1 m of width, length, and depth, respectively, and W:F ratio of 4.0), H2 (1.5x1x1 and W:F of 2.5), H3 (2x1x0.5 and W:F of 1.5) and H4 (2×1×2 and W:F of 1.5). Simulations showed that silt pits with larger W:F ratios could store water for longer periods and feed water to a farther horizontal distance within the soil compared to silt pits with smaller W:F ratios. H1 took the longest to dry out, whereby it took 14 to 19 hours longer to dry out compared to than H2, H3 and H4. H1 and H3 could feed water as far as 80 cm away from the pit more than H2 and H4 (60 and 50 cm, respectively). This is because silt pits with larger W:F ratios had larger horizontal water flow than the vertical water flow. Meanwhile, the depth of a silt pit should not be below the oil palm active rooting depth, which water would flow out of reach by the roots. This study is a preliminary work to a field experiment where simulations from this paper would be validated against measurements obtained in the field before recommending the use of silt pits and their size to be constructed in oil palm plantations.

Silt pit is one of the recommended soil water conservation practices in oil palm plantations. It is commonly regarded that the larger and deeper the silt pit, the more effective the pit would be to conserve soil water. This hypothesis was tested in this paper, where the effectiveness of four silt pit dimensions on conserving soil water in the oil palm active rooting zone was simulated using the HYDRUS 2D model. These silt pits had different sizes and total wet wall-to-floor area ratio (W:F): H1 silt pit (1x1x1 m of width, length, and depth, respectively, and W:F ratio of 4.0), H2 (1.5x1x1 and W:F of 2.5), H3 (2x1x0.5 and W:F of 1.5) and H4 (2×1×2 and W:F of 1.5). Simulations showed that silt pits with larger W:F ratios could store water for longer periods and feed water to a farther horizontal distance within the soil compared to silt pits with smaller W:F ratios. H1 took the longest to dry out, whereby it took 14 to 19 hours longer to dry out compared to than H2, H3 and H4. H1 and H3 could feed water as far as 80 cm away from the pit more than H2 and H4 (60 and 50 cm, respectively). This is because silt pits with larger W:F ratios had larger horizontal water flow than the vertical water flow. Meanwhile, the depth of a silt pit should not be below the oil palm active rooting depth, which water would flow out of reach by the roots. This study is a preliminary work to a field experiment where simulations from this paper would be validated against measurements obtained in the field before recommending the use of silt pits and their size to be constructed in oil palm plantations.

This book contains information on pineapples cultivation on tropical peat soil and it discusses some essential elements for sustainable cultivation of pineapples on this type of organic soils. Therefore, the book is designed as a quick reference text, with the aim that farmers, students and scientists with little experience on pineapples cultivation on organic soils are able to grasp the rudiments of their cultivation on these soils. This book will also be of significant interest to those working in the applied sciences.

This book contains information on pineapples cultivation on tropical peat soil and it discusses some essential elements for sustainable cultivation of pineapples on this type of organic soils. Therefore, the book is designed as a quick reference text, with the aim that farmers, students and scientists with little experience on pineapples cultivation on organic soils are able to grasp the rudiments of their cultivation on these soils. This book will also be of significant interest to those working in the applied sciences.

High demands for palm oil world wide induce the expansion of oil palm plantations in Malaysia. Malaysian soils which are highly weathered require high nitrogen fertilizer input in order to maintain high yield output, resulting in increase in production cost as well as inducing negative impacts to the environment. It is crucial to understand the performance of different oil palm genotypes in taking up nitrogen to increase nitrogen use efficiency, minimize environmental pollution caused by leached nitrate and maximize plantation profit, while maintaining sustainable agriculture practices. 15N labelling method was utilized in a greenhouse study to quantify the nitrogen up-take performance of nine oil palm genotypes at 6 and 9 months after planting. Measurements of total dry matter, total N, and percentage N derived from fertilizer (%NdFF) were carried out during the study. At 6 month old, oil palms of different genotypes did not show any difference in nitrogen uptake with and without P fertilizer applications. However, 9 months old oil palms demonstrated significant differences between the genotypes in total dry matter production and total N taken up, hence, resulting in significant differences in N derived from fertilizer among genotypes. Oil palms at 9 months old also showed significant effects in the N uptake as affected by P fertilizer application. Genotype A (14/34 x 2367/17) demonstrated significantly higher nitrogen uptake compared to other genotypes, except for genotype F (9/103 x 2318/17). Thus, the 15N labelling technique could serve as a useful assessment to the nitrogen uptake abilities of oil palm genotypes.

High demands for palm oil world wide induce the expansion of oil palm plantations in Malaysia. Malaysian soils which are highly weathered require high nitrogen fertilizer input in order to maintain high yield output, resulting in increase in production cost as well as inducing negative impacts to the environment. It is crucial to understand the performance of different oil palm genotypes in taking up nitrogen to increase nitrogen use efficiency, minimize environmental pollution caused by leached nitrate and maximize plantation profit, while maintaining sustainable agriculture practices. 15N labelling method was utilized in a greenhouse study to quantify the nitrogen up-take performance of nine oil palm genotypes at 6 and 9 months after planting. Measurements of total dry matter, total N, and percentage N derived from fertilizer (%NdFF) were carried out during the study. At 6 month old, oil palms of different genotypes did not show any difference in nitrogen uptake with and without P fertilizer applications. However, 9 months old oil palms demonstrated significant differences between the genotypes in total dry matter production and total N taken up, hence, resulting in significant differences in N derived from fertilizer among genotypes. Oil palms at 9 months old also showed significant effects in the N uptake as affected by P fertilizer application. Genotype A (14/34 x 2367/17) demonstrated significantly higher nitrogen uptake compared to other genotypes, except for genotype F (9/103 x 2318/17). Thus, the 15N labelling technique could serve as a useful assessment to the nitrogen uptake abilities of oil palm genotypes.

This study investigates the impacts of short-term (1.5-year) heavy (SHG) and long-term (33-year) moderate (LMG) grazing intensities on the chemical properties of soil in the tropical pasture ecosystems. Two pastures with different grazing intensities and two ungrazed pastures were sampled at the varied depths of 0-10 and 10-20 cm in the Livestock Section of Universiti Putra Malaysia (UPM), Selangor, Malaysia. The EC and pH values in both the moderately and heavily grazed pastures were higher than the ungrazed ones. Meanwhile, the total carbon (TC) in the surface soil of the grazed pastures was 63% and 57% higher than the ungrazed pastures in the LMG and SHG pastures, respectively. The concentration of total nitrogen (TN) was not affected (P > 0.05) by livestock grazing. The concentration of available phosphorus (AP) in the surface soil and grazed pasture was significantly greater than the sub-surface soil and ungrazed pastures in the LMG pastures. The AP concentration in the grazed pasture and surface soil was 62.2% and 68.4% less than the ungrazed pasture and subsurface soil in the SHG pasture, respectively. It was found that the concentration of exchangeable cations (Ca+2, Mg+2, and K+) was affected by grazing. In particular, the concentration of exchangeable cations in both the moderately and heavily grazed pastures was also observed to be less than the ungrazed ones, except for Mg+2 in the LMG pasture. These results indicate that the impacts of livestock grazing on soil chemical properties were almost limited to the surface soil. After 33 years of moderate grazing, greater values were found for pH, EC, AP, and Mg+2 whereas lower values were stated for TN, TC, Ca+2, and K+. As compared to the ungrazed control, the concentrations of AP, TN, Ca+2, Mg+2, and K+ decreased after 1.5 years of heavy grazing.

This study investigates the impacts of short-term (1.5-year) heavy (SHG) and long-term (33-year) moderate (LMG) grazing intensities on the chemical properties of soil in the tropical pasture ecosystems. Two pastures with different grazing intensities and two ungrazed pastures were sampled at the varied depths of 0-10 and 10-20 cm in the Livestock Section of Universiti Putra Malaysia (UPM), Selangor, Malaysia. The EC and pH values in both the moderately and heavily grazed pastures were higher than the ungrazed ones. Meanwhile, the total carbon (TC) in the surface soil of the grazed pastures was 63% and 57% higher than the ungrazed pastures in the LMG and SHG pastures, respectively. The concentration of total nitrogen (TN) was not affected (P > 0.05) by livestock grazing. The concentration of available phosphorus (AP) in the surface soil and grazed pasture was significantly greater than the sub-surface soil and ungrazed pastures in the LMG pastures. The AP concentration in the grazed pasture and surface soil was 62.2% and 68.4% less than the ungrazed pasture and subsurface soil in the SHG pasture, respectively. It was found that the concentration of exchangeable cations (Ca+2, Mg+2, and K+) was affected by grazing. In particular, the concentration of exchangeable cations in both the moderately and heavily grazed pastures was also observed to be less than the ungrazed ones, except for Mg+2 in the LMG pasture. These results indicate that the impacts of livestock grazing on soil chemical properties were almost limited to the surface soil. After 33 years of moderate grazing, greater values were found for pH, EC, AP, and Mg+2 whereas lower values were stated for TN, TC, Ca+2, and K+. As compared to the ungrazed control, the concentrations of AP, TN, Ca+2, Mg+2, and K+ decreased after 1.5 years of heavy grazing.

Nitrogen is the most limiting nutrient in rice production. N fertilizer is susceptible to losses when the time of application does not match with period of crop demand. A glasshouse experiment was conducted to determine the critical time of nitrogen fertilizer application at panicle initiation on grain yield of two Malaysian rice cultivars (MR219 and MR232). The experiment consisted of five N treatments applied each at 60 kg ha-1 at 45 (NI), 50 (N2), 55 (N3), 60 (N4) and 65 (N5) days after seeding (DAS) with five replications. Prior to this stage, a total of 75 kg N ha-1 was applied during vegetative growth stage (at 15 and 35 DAS). Plant physiological parameters such as height, SPAD value and LAI showed statistical difference among some treatments. Application of N also resulted in an increase in plant biomass. The results demonstrate that the split application of fertilizer N at PI stage (55 DAS) significantly increased percentage of filled grains, 1000-grain weight and total grain yield. Incorrect timing of N application (65 DAS) at P1 stage, drastically reduced rice yield to approximately 39% for MR2 19 and 17% for MR232. Farmers should be advised to apply N between 50 DAS and 55 DAS, even though application of N at 55 DAS was far better than 50 DAS in terms of yield parameters.

Nitrogen is the most limiting nutrient in rice production. N fertilizer is susceptible to losses when the time of application does not match with period of crop demand. A glasshouse experiment was conducted to determine the critical time of nitrogen fertilizer application at panicle initiation on grain yield of two Malaysian rice cultivars (MR219 and MR232). The experiment consisted of five N treatments applied each at 60 kg ha-1 at 45 (NI), 50 (N2), 55 (N3), 60 (N4) and 65 (N5) days after seeding (DAS) with five replications. Prior to this stage, a total of 75 kg N ha-1 was applied during vegetative growth stage (at 15 and 35 DAS). Plant physiological parameters such as height, SPAD value and LAI showed statistical difference among some treatments. Application of N also resulted in an increase in plant biomass. The results demonstrate that the split application of fertilizer N at PI stage (55 DAS) significantly increased percentage of filled grains, 1000-grain weight and total grain yield. Incorrect timing of N application (65 DAS) at P1 stage, drastically reduced rice yield to approximately 39% for MR2 19 and 17% for MR232. Farmers should be advised to apply N between 50 DAS and 55 DAS, even though application of N at 55 DAS was far better than 50 DAS in terms of yield parameters.

The study was conducted to compare the benefits and costs of in situ burning of pineapple residues with removal of pineapple residues (before replanting) in pineapple cultivation on tropical peat. Treatments used were: (i) residues (leaves, crowns, and peduncles) removal followed by fertilization (REF) and (ii) residues (leaves, crowns, and peduncles) burnt followed by fertilization (usual practice) (REF). At the end of the study, the average fruit weight per treatment was recorded. Fruit weight multiplied by the plant density of 56,250 will give the total yield per hectare. The product of the total yield/ha and farm-gate price will give the gross revenue of crop production. Cost of labour was based on the wage system practiced by the pineapple estates. Farm-gate market prices were used for assessing farm materials and other inputs. Cost of land was based on the annual rental value for pineapple plantations. An interest rate of 12% was charged on the capital used. Under the Environmental Quality Act, 1978 amended in 1998, and according to the Air Pollutant Index (API) the polluters have to pay the principal fine imposed for polluting the air through open burning ofpineapple residues. All these costs will be taken into account when calculating the production cost ofpineapple. Burning did not significantly increase yield. Cost and benefit analysis revealed that removal ofpineapple residues (RRF) is more economically viable than burning the residues (REF). Adoption ofRRF requires further studies in selecting the most suitable method of enhancing the quality of the environment or developing product(s) of commercial value from pineapple residues. The cost of the study should be bome partly by the government, the pineapple estates, and the public.

The study was conducted to compare the benefits and costs of in situ burning of pineapple residues with removal of pineapple residues (before replanting) in pineapple cultivation on tropical peat. Treatments used were: (i) residues (leaves, crowns, and peduncles) removal followed by fertilization (REF) and (ii) residues (leaves, crowns, and peduncles) burnt followed by fertilization (usual practice) (REF). At the end of the study, the average fruit weight per treatment was recorded. Fruit weight multiplied by the plant density of 56,250 will give the total yield per hectare. The product of the total yield/ha and farm-gate price will give the gross revenue of crop production. Cost of labour was based on the wage system practiced by the pineapple estates. Farm-gate market prices were used for assessing farm materials and other inputs. Cost of land was based on the annual rental value for pineapple plantations. An interest rate of 12% was charged on the capital used. Under the Environmental Quality Act, 1978 amended in 1998, and according to the Air Pollutant Index (API) the polluters have to pay the principal fine imposed for polluting the air through open burning ofpineapple residues. All these costs will be taken into account when calculating the production cost ofpineapple. Burning did not significantly increase yield. Cost and benefit analysis revealed that removal ofpineapple residues (RRF) is more economically viable than burning the residues (REF). Adoption ofRRF requires further studies in selecting the most suitable method of enhancing the quality of the environment or developing product(s) of commercial value from pineapple residues. The cost of the study should be bome partly by the government, the pineapple estates, and the public.

The study was carried out to determine the most effective, efficient, and profitable combination of fertilizer regime and pineapple residue management practice for pineapple grown on tropical peat. Three residue management practices, namely; (i) In situ decomposition of pineapple residue without any disturbance (R1), (ii) Stacking of pineapple residue slashed and raked from 0.6 m x 10 m beds into 0.9 x 10 m beds (R2), and (iii) In situ burning of pineapple residue (RJ) were used in combination with three fertilizer regimes; (i) application of P and K at the 651h, 135th, 19151, and 233'"d days after planting (F1), (ii) application of P and K at the 651h , 135t1 ·, and 191st days after planting (F2), and (iii) application of P and K at the 65t11 , 1351 and 191'1 days after planting but sharing fertilizer amount of the 23Jrd day between the 1351h and 19151 days (F3). The effect of the three residue management practices on P and K uptake as well as fruit yield was not significant. Similar observation was made for the three fertilizer regimes. In terms of cost, R1 was the cheapest residue management practice with RJ being the most expensive practice. F2 emerged the cheapest fertilizer regime while F1 was the most expensive regime. The most cost effective treatment combination was R1F2. Burning, stacking of pineapple residue in rows or leaving pineapple residue to decompose in situ did not improve K and P uptake as well as fruit yield. The application of K (188 kg/hay and P (7 kg/hay fertilizers at 23Jrd day after planting is not necessary and lJy omitting it the practice could save as much as RM 187. 98/ha. The application of muriate of potash and China phosphate rock at the 651h, 135t1 ·, and 19151 days (F2) under in situ decomposition of pineapple residue (R1) looks promising in terms of the cost effectiveness.

The study evaluates the existing and potential fertilizer programmes and pineapple residue management practices in order to come out with a fertilization programme which is economically viable. The fertilizer programmes adopted were: (i) application of N (176, 176, 176, and 176 kg ha-1 ), P (11, 11, 7, and 7 kg herJ), and K (89, 89, 188, and 188 kg ha-1 ) fertilizers at 65, 135, 191, and 233 days after planting (FP1), respectively (the usual practice); (ii) application of N (176, 176, and 176 kg ha-J ) P (11, 11, and 7 kg herJ) and K (89, 89, and 188 kg ha-J) fertilizers at 65, 135, and 191 days after planting (FP2), respectively; and (iii) application of N (176,264, and 264 kg ha-1 ) P (11,14, and 11 kg ha-1 ) and K (89,183, and 285 kg ha-J) fertilizers at 65, 135, and 191 days after planting (FP3), respectively. Pineapple residue management practices used were: (i) in situ decomposition of pineapple residue without any interference (RMl); (ii) stacking of pineapple residue (leaves, crowns, and peduncles) slashed, and raked from 0.6 m x 10m beds into 0.9 m x 10m beds (RM2-zero bum technique); and (iii) in situ burning of pineapple leaves, crowns, and peduncles (the usual practice) (RM3). Combinations of the residue management practices and fertilizer programmes gave the following treatments: RM1FP1, RM1FP2, RM1FP3, RM2FP1, RM2FP2, RM2FP3, RM3FP1, RM3FP2, and RM3FP3. Neither of the fertilization programmes (FP1, FP2, and FP3) nor residue management practices (RM1, RM2, and RM3)significantly improved fruit yield. FP2 emerged as the least expensive programme followed by FP3, and then FP1. The cheapest residue management practice was RM1, followed by RM2, and RM3. RM1FP2 emerged the most economic treatment combination. Zero-bum technique (RM2), in situ decomposition of pineapple residues without any interference (RM1), in situ burning of pineapple residues did not significantly improve fruit yield, but practicing RM1 in pineapple cultivation on tropical peat is economi

The study was carried out to determine the most effective, efficient, and profitable combination of fertilizer regime and pineapple residue management practice for pineapple grown on tropical peat. Three residue management practices, namely; (i) In situ decomposition of pineapple residue without any disturbance (R1), (ii) Stacking of pineapple residue slashed and raked from 0.6 m x 10 m beds into 0.9 x 10 m beds (R2), and (iii) In situ burning of pineapple residue (RJ) were used in combination with three fertilizer regimes; (i) application of P and K at the 651h, 135th, 19151, and 233'"d days after planting (F1), (ii) application of P and K at the 651h , 135t1 ·, and 191st days after planting (F2), and (iii) application of P and K at the 65t11 , 1351 and 191'1 days after planting but sharing fertilizer amount of the 23Jrd day between the 1351h and 19151 days (F3). The effect of the three residue management practices on P and K uptake as well as fruit yield was not significant. Similar observation was made for the three fertilizer regimes. In terms of cost, R1 was the cheapest residue management practice with RJ being the most expensive practice. F2 emerged the cheapest fertilizer regime while F1 was the most expensive regime. The most cost effective treatment combination was R1F2. Burning, stacking of pineapple residue in rows or leaving pineapple residue to decompose in situ did not improve K and P uptake as well as fruit yield. The application of K (188 kg/hay and P (7 kg/hay fertilizers at 23Jrd day after planting is not necessary and lJy omitting it the practice could save as much as RM 187. 98/ha. The application of muriate of potash and China phosphate rock at the 651h, 135t1 ·, and 19151 days (F2) under in situ decomposition of pineapple residue (R1) looks promising in terms of the cost effectiveness.

The study evaluates the existing and potential fertilizer programmes and pineapple residue management practices in order to come out with a fertilization programme which is economically viable. The fertilizer programmes adopted were: (i) application of N (176, 176, 176, and 176 kg ha-1 ), P (11, 11, 7, and 7 kg herJ), and K (89, 89, 188, and 188 kg ha-1 ) fertilizers at 65, 135, 191, and 233 days after planting (FP1), respectively (the usual practice); (ii) application of N (176, 176, and 176 kg ha-J ) P (11, 11, and 7 kg herJ) and K (89, 89, and 188 kg ha-J) fertilizers at 65, 135, and 191 days after planting (FP2), respectively; and (iii) application of N (176,264, and 264 kg ha-1 ) P (11,14, and 11 kg ha-1 ) and K (89,183, and 285 kg ha-J) fertilizers at 65, 135, and 191 days after planting (FP3), respectively. Pineapple residue management practices used were: (i) in situ decomposition of pineapple residue without any interference (RMl); (ii) stacking of pineapple residue (leaves, crowns, and peduncles) slashed, and raked from 0.6 m x 10m beds into 0.9 m x 10m beds (RM2-zero bum technique); and (iii) in situ burning of pineapple leaves, crowns, and peduncles (the usual practice) (RM3). Combinations of the residue management practices and fertilizer programmes gave the following treatments: RM1FP1, RM1FP2, RM1FP3, RM2FP1, RM2FP2, RM2FP3, RM3FP1, RM3FP2, and RM3FP3. Neither of the fertilization programmes (FP1, FP2, and FP3) nor residue management practices (RM1, RM2, and RM3)significantly improved fruit yield. FP2 emerged as the least expensive programme followed by FP3, and then FP1. The cheapest residue management practice was RM1, followed by RM2, and RM3. RM1FP2 emerged the most economic treatment combination. Zero-bum technique (RM2), in situ decomposition of pineapple residues without any interference (RM1), in situ burning of pineapple residues did not significantly improve fruit yield, but practicing RM1 in pineapple cultivation on tropical peat is economi

This research quantifies P, K, Ca and Mg inputs, losses, retention in soil, and uptake and returns for burnt and unburnt pineapple residue in management practices. Treatments used were: leaves residue removed and no fertilization (LRRNF), leaves residue burnt and no fertilization (LRBNF), leaves residue removed and fertilization (LRRF), and leaves residue burnt and fertilization (the usual practice) (LRBF). Nitrogen, P and K were applied in the forms of urea (46.00% N), China phosphate rock (CPR 14.00% P) and muriate of potash (MOP 49.80% K) at the rates of 701.04, 35.56, and 556.56 kg N, K, and P per ha respectively. Rainfall simulator was used for surface runoff measurement on burnt plots before planting. Soil sampling at the depths of 0-5, 525 and . 25 cm were done before planting, during and after fertilization stages. Extractable P, K, Ca and Mg were extracted using the double-acid method. The subtraction method was used to estimate P, K, Ca and Mg leached (kg per haY. At maturity, plants were sampled from each treatment and partitioned into roots, stem, leaves, fruit, crown and peduncle, and the dry weights, of P, K, Ca and Mg contents determined. Molybdate blue method and atomic absorption spectrophotometer were used in determining P, K, Ca and Mg in soil, plant parts and rainwater, K, Ca and Mg additions from fertilizer, ash and precipitation for LRBF were estimated at 54.25, 816.68, 103.31 and 23.54 kg per ha, and those of LRRF (fertilizer and precipitation) were 35.56, 576.05, 100.17, and 4.93 kg P, K, Ca, and Mg per ha, respectively. The estimated amounts of P, K, Ca and Mg lost under LRBF were 18.44, 300.45, 66.06 and 8.63 kg per ha and in the case of LRRF, the losses were 23.19, 244.88, 45.79 and 5.49 kg per ha. Leaching was the major source of P, K, Ca and Mg loss for both practices and this was attributed to inappropriate fertilization frequency. A positive balance of P, K, Ca and Mg was recorded for LRBF, 46.00% P, 28.00% K, 20.00% Ca and 27.00% Mg w

This research quantifies P, K, Ca and Mg inputs, losses, retention in soil, and uptake and returns for burnt and unburnt pineapple residue in management practices. Treatments used were: leaves residue removed and no fertilization (LRRNF), leaves residue burnt and no fertilization (LRBNF), leaves residue removed and fertilization (LRRF), and leaves residue burnt and fertilization (the usual practice) (LRBF). Nitrogen, P and K were applied in the forms of urea (46.00% N), China phosphate rock (CPR 14.00% P) and muriate of potash (MOP 49.80% K) at the rates of 701.04, 35.56, and 556.56 kg N, K, and P per ha respectively. Rainfall simulator was used for surface runoff measurement on burnt plots before planting. Soil sampling at the depths of 0-5, 525 and . 25 cm were done before planting, during and after fertilization stages. Extractable P, K, Ca and Mg were extracted using the double-acid method. The subtraction method was used to estimate P, K, Ca and Mg leached (kg per haY. At maturity, plants were sampled from each treatment and partitioned into roots, stem, leaves, fruit, crown and peduncle, and the dry weights, of P, K, Ca and Mg contents determined. Molybdate blue method and atomic absorption spectrophotometer were used in determining P, K, Ca and Mg in soil, plant parts and rainwater, K, Ca and Mg additions from fertilizer, ash and precipitation for LRBF were estimated at 54.25, 816.68, 103.31 and 23.54 kg per ha, and those of LRRF (fertilizer and precipitation) were 35.56, 576.05, 100.17, and 4.93 kg P, K, Ca, and Mg per ha, respectively. The estimated amounts of P, K, Ca and Mg lost under LRBF were 18.44, 300.45, 66.06 and 8.63 kg per ha and in the case of LRRF, the losses were 23.19, 244.88, 45.79 and 5.49 kg per ha. Leaching was the major source of P, K, Ca and Mg loss for both practices and this was attributed to inappropriate fertilization frequency. A positive balance of P, K, Ca and Mg was recorded for LRBF, 46.00% P, 28.00% K, 20.00% Ca and 27.00% Mg w

Humic acids (HA) are widely researched and exploited compounds due to their exceptional chemical and physical properties. However, information on tropical-based HA is still lacking. This attempted to characterize HA derived from tropical peat and POME using chemical and physical methods. Elemental analysis of the HA showed that C ranged between 48.94 and 57.87%, H between 4.90 and 8.26%, N between 1.93 and 8.05% and 0 between 30.96 and 40.85%. The functional group analysis indicated that peat-derived HA were more reactive than those derived from POME. Optical density and spectral examinations revealed that the HA had varying degrees of aromaticity. Generally, data obtained from the HAs studied (particularly from peat) agreed closely with those reported elsewhere.

Humic acids (HA) are widely researched and exploited compounds due to their exceptional chemical and physical properties. However, information on tropical-based HA is still lacking. This attempted to characterize HA derived from tropical peat and POME using chemical and physical methods. Elemental analysis of the HA showed that C ranged between 48.94 and 57.87%, H between 4.90 and 8.26%, N between 1.93 and 8.05% and 0 between 30.96 and 40.85%. The functional group analysis indicated that peat-derived HA were more reactive than those derived from POME. Optical density and spectral examinations revealed that the HA had varying degrees of aromaticity. Generally, data obtained from the HAs studied (particularly from peat) agreed closely with those reported elsewhere.

Basic research conducted on humic acid (HA) in tropical soils is limited. A study was conducted to characterize HA extracted from tropical peat by elemental and functional group analyses, infrared (IR) spectra and by direct examination on HA using scanning electron microscopy (SEM). From the elemental analysis it was found that C ranged from 40.26 - 53.26%, H 4.84 - 6.36%,038.39 - 51.62%, N 1.51- 2.64%, and P 0.02 - 0.06%. Studies of functional groups indicated that the carboxyl group present in HA of tropical peat was about twice as high as that of phenolic hydroxyl groups. From IR spectra, the HA had an aromatic character. Results of IR analysis also exhibited consistently similar spectra, demonstrating that regardless of place of origin, the extracted humic compound had a similar structure and was composed of the same functional groups. Electron microscopic examination of dried HA showed a sub-angular blocky shape which varied in size. All extracted HA exhibited similar form.

The mineralogy and charge characteristics of 7 soils from the Philippines, Indonesia and Malaysia were studied. The soils consisted of an Entisol, 3 Alfisols, an Andisol and 2 Oxisols. Smectite, mica and quartz were present in the clay fraction of the Entisol. In the Alfisols, smectite and kaolinite were the dominant minerals. The Andisol was dominated by halloysite, whereas the Oxisols were dominated by kaolinite and oxides. The amount of kaolinite increased towards the surface, while halloysite decreased, indicating the transformation of halloysite to kaolinite during the course of weathering. Differences in mineralogy of the various soil types were reflected clearly in the differences in charge characteristics. Soils with smectite (Entisol and Alfisol) had high a negative charge. The Andisol, which contained halloysite, and the Oxisol, with kaolinite and oxides, had high amounts ofpositive charge, but moderate amounts ofnegative charge. The availability ofCa in the soils depended upon exchangeable Ca and the efJective cation exchange capacity (ECEC).

Basic research conducted on humic acid (HA) in tropical soils is limited. A study was conducted to characterize HA extracted from tropical peat by elemental and functional group analyses, infrared (IR) spectra and by direct examination on HA using scanning electron microscopy (SEM). From the elemental analysis it was found that C ranged from 40.26 - 53.26%, H 4.84 - 6.36%,038.39 - 51.62%, N 1.51- 2.64%, and P 0.02 - 0.06%. Studies of functional groups indicated that the carboxyl group present in HA of tropical peat was about twice as high as that of phenolic hydroxyl groups. From IR spectra, the HA had an aromatic character. Results of IR analysis also exhibited consistently similar spectra, demonstrating that regardless of place of origin, the extracted humic compound had a similar structure and was composed of the same functional groups. Electron microscopic examination of dried HA showed a sub-angular blocky shape which varied in size. All extracted HA exhibited similar form.

The mineralogy and charge characteristics of 7 soils from the Philippines, Indonesia and Malaysia were studied. The soils consisted of an Entisol, 3 Alfisols, an Andisol and 2 Oxisols. Smectite, mica and quartz were present in the clay fraction of the Entisol. In the Alfisols, smectite and kaolinite were the dominant minerals. The Andisol was dominated by halloysite, whereas the Oxisols were dominated by kaolinite and oxides. The amount of kaolinite increased towards the surface, while halloysite decreased, indicating the transformation of halloysite to kaolinite during the course of weathering. Differences in mineralogy of the various soil types were reflected clearly in the differences in charge characteristics. Soils with smectite (Entisol and Alfisol) had high a negative charge. The Andisol, which contained halloysite, and the Oxisol, with kaolinite and oxides, had high amounts ofpositive charge, but moderate amounts ofnegative charge. The availability ofCa in the soils depended upon exchangeable Ca and the efJective cation exchange capacity (ECEC).

Granite gneiss occurs sporadically throughout Sri Lanka. Depending on the climatic conditions and topography of the area, the rock undergoes different degrees of chemical weathering. The mineralogy and chemical properties off four common granite gneiss soils occuning in three agro-ecological zones in Sri Lanka were studied. The soil in the wet zone is low in pH and basic exchangeable cations, while the soils in the wet zone are high in pH and basic exchangeable cations. The colour of the soils changes from yellowish-brown to red as the soils get drier, pesumably due to the presence of haematite and/or goethite. Kaolinite, halloysite and smectite are present in all the soils irrespective of the climatic conditions; the amount of halloysite decreases towards the surface. Biotite is abundant in the soil of the intermediate and dry zones, but is absent in the soil ofthe wet tone. Gibbsite is present in the highly weathered soil of the wet zone. The concentration of Ca in soil solution is dependent on the amount in the soils existing in the form of exchangeable Ca. Additionally, the solution Ca concentration is significantly correlated with the soil ECEC and the ECEC/CEC ratio.

Granite gneiss occurs sporadically throughout Sri Lanka. Depending on the climatic conditions and topography of the area, the rock undergoes different degrees of chemical weathering. The mineralogy and chemical properties off four common granite gneiss soils occuning in three agro-ecological zones in Sri Lanka were studied. The soil in the wet zone is low in pH and basic exchangeable cations, while the soils in the wet zone are high in pH and basic exchangeable cations. The colour of the soils changes from yellowish-brown to red as the soils get drier, pesumably due to the presence of haematite and/or goethite. Kaolinite, halloysite and smectite are present in all the soils irrespective of the climatic conditions; the amount of halloysite decreases towards the surface. Biotite is abundant in the soil of the intermediate and dry zones, but is absent in the soil ofthe wet tone. Gibbsite is present in the highly weathered soil of the wet zone. The concentration of Ca in soil solution is dependent on the amount in the soils existing in the form of exchangeable Ca. Additionally, the solution Ca concentration is significantly correlated with the soil ECEC and the ECEC/CEC ratio.