A study was carried out to test the effects of three rates of TSP （triple superphosphate） （0, 50, and 100 mg·kg^-1 P） on growth of broom with and without radiata pine seedlings and to determine the relationsh...A study was carried out to test the effects of three rates of TSP （triple superphosphate） （0, 50, and 100 mg·kg^-1 P） on growth of broom with and without radiata pine seedlings and to determine the relationships between P concentrations in the broom shoot and dry matter yields with soil plant-available P （Bray-2 P）. A bulk sample of soil was collected from Kaweka forest at soil depth of 0-10 cm, in New Zealand on March 11, 2001. The forest area was not supplied with fertiliser at least 30 years. The results show that TSP application increased P avail- ability in the soil. The P availability concentration in soil of broom with radiata pine seedlings was higher than that in soil of broom alone. Bray-2 P concentrations had a significant logarithmic relationship with Pcon- centrations of broom shoot and an exponential relationship with dry matter weight of whole broom plant.展开更多
A study was carried out to investigate changes in the soil plant-available P,the P nutrition and the growth of Pinus radiata seedlings grown in association with understory,broom（Cytisus scoparius L.） or ryegrass（Lo...A study was carried out to investigate changes in the soil plant-available P,the P nutrition and the growth of Pinus radiata seedlings grown in association with understory,broom（Cytisus scoparius L.） or ryegrass（Lolium multiflorum） on Orthic Allophanic Soil,following the application of three rates of triple superphosphate（TSP）（0,50,and 100 mg·kg^-1P） under a glasshouse condition.The application of P fertilizer enhanced P availability in the rhizospheric of radiata seedlings and the bulk soils in a P-deficient site.P availability in the rhizospheric soils of ryegrass and broom,grown in association with radiata,were also increased by the presence of radiata roots.P concentrations in new shoot needles,old shoot needles,stem and roots of radiata pine increased with increase rates of TSP application,but the effects of ryegrass and broom on P nutrition of radiata seedlings depended on the soil P status.In the absence of P fertilizer addition（control treatment）,P concentrations in new shoot needles,old shoot needles,stem,and roots of radiata grown in association with broom were higher than those with ryegrass,whereas,when P fertilizer was added（50 and 100 mg·kg^-1） the P concentration was lower.This is probably related to the growth of broom that may have removed much of the plant-available P in the soil as indicated by the consistently lower Bray-2 P concentration in the rhizosphere soil of radiata in association with broom than that in the rhizosphere soil of radiata in association with grass at the two high P rates.Furthermore,in the high P fertile soil（application rate of 100 mg·kg^-1）,the dry matter yield of radiata was lower when it was grown with broom than with ryegrass.This result suggests that in moderate to high P fertile soils,P.radiata seedlings grow better with ryegrass than with broom,because broom grows vigorously in high P fertile soil and competes with P.radiata for P and perhaps for other nutrients as well.展开更多
Changes in phosphorus （P） fractions in a P deficient allophanic soil under P. radiata seedlings grown with broom （Cytisus scoparius L.） and ryegrass （Lolium multiflorum） in pots were studied 14 months after the ...Changes in phosphorus （P） fractions in a P deficient allophanic soil under P. radiata seedlings grown with broom （Cytisus scoparius L.） and ryegrass （Lolium multiflorum） in pots were studied 14 months after the application of triple superphosphate at the rates of 0, 50, and 100 pg.g^-1, to determine the fate of fertiliser-derived P in the rhizosphere soils. Application of P fertiliser increased NaOH-Pi, NaOH-Po, and H2SO4-Pi concentrations in the soil, but decreased the residual-P concentration. The resin-Pi concentration, which is ex- tremely low in this soil （1 to μgg^-1 ）, remained the same. The majority of the added fertiliser P was however recovered in the NaOH-Pi fraction （40%-49%）. This is due to the high P fixation in this soil （92%）. The second highest P recovery was in NaOH-Po fraction （7%-19%）. Under P deficient condition or addition at the rate of 0 μg.g^-6, the NaOH-Pi concentration in the radiata rhizosphere soil was lower than that in the bulk soil and broom and grass rhizosphere soils. This may be due to higher oxalate production by the roots and mycorrhiza under P deficient conditions which released some ＆the P fixed to the soils in the rhizosphere, which needs to be tested in future studies.展开更多
Changes in phosphorus (P) fractions in a P deficient allophanic soil under P. radiata seedlings grown with broom (Cytisus scoparius L.) and ryegrass (Lolium multiflorum) in pots were studied 14 months after the applic...Changes in phosphorus (P) fractions in a P deficient allophanic soil under P. radiata seedlings grown with broom (Cytisus scoparius L.) and ryegrass (Lolium multiflorum) in pots were studied 14 months after the application of triple superphosphate at the rates of 0, 50, and 100 μg·g-1, to determine the fate of fertiliser-derived P in the rhizosphere soils. Application of P fertiliser increased NaOH-Pi, NaOH-Po, and H2SO4-Pi concentrations in the soil, but decreased the residual-P concentration. The resin-Pi concentration, which is extremely low in this soil (1 to 3 μg·g-1 ), remained the same. The majority of the added fertiliser P was however recovered in the NaOH-Pi fraction (40%?49%). This is due to the high P fixation in this soil (92%). The second highest P recovery was in NaOH-Po fraction (7%?19%). Under P deficient condition or addition at the rate of 0 μg·g-1, the NaOH-Pi concentration in the radiata rhizosphere soil was lower than that in the bulk soil and broom and grass rhizosphere soils. This may be due to higher oxalate production by the roots and mycorrhiza under P deficient conditions which released some of the P fixed to the soils in the rhizosphere, which needs to be tested in future studies.展开更多
Silvicultural approaches at forest plantations with wider initial tree spacing have created potential for increased understory vegetation growth in response to increased light and greater nutrient resources. In conse-...Silvicultural approaches at forest plantations with wider initial tree spacing have created potential for increased understory vegetation growth in response to increased light and greater nutrient resources. In conse- quence understory vegetation can fill a more important role in forest ecosystems, especially in interactions （competi- tion or facilitation） between understorey vegetation and forests trees that might affect tree growth and nutrition. Considerable research has been carried out on plant inter- ference. However, the experimental designs used in these studies vary from one study to another, and from species to species depending on the aims, objectives and practicalities of the studies. Thus there is no optimum design for com- petition experiments. This review discusses designs avail- able in studying plant interferences in a glasshouse, particularly the effects of below-ground interaction of understorey vegetation and forest trees.展开更多
Development of gamma irradiated high moisture traditional dishes derived from locally traditional récipe aimed for specific target groups as ready to eat foods for ensuring the safety, quality, and security purpo...Development of gamma irradiated high moisture traditional dishes derived from locally traditional récipe aimed for specific target groups as ready to eat foods for ensuring the safety, quality, and security purposes have been conducted. The formation of free radicals in the traditional foods induced by ionizing radiation is a part of toxicological studies on irradiated traditional foods was to provide local scientific data base on safe- ty issues.The different foods such as steamed gold fish, spicy curry beef and soy sauces beef were individually vacuum packed in a laminate pouch of PET 12 μm/LDPE 2 μm/AL-Foil 7 μm/LDPE 2 μm/LLDPE 50 μm (PET/Al-Foil/ LLDPE), then kept at frozen state. The frozen samples were maintained in cryogenic condition along the irradiation process by placing the samples in styrofoam boxes filled with dry ice then irradiated with gamma rays at the dose of 45 kGy. The irradiated samples were kept and stored at normal temperature prior to test. Both irradiated conventional rat’s feed at normal temperature with the dose of 4 kGy and unirradiated one as control were also made. Irradiated and unirradiated samples were sent to animal laboratory, and fed into individual female Sprague Dawley rat as member of a group. The parameters observed were body weight changed of rats, toxicological test to observe the effect free radicals formation in rat’s blood by using malon-dialdehyde (MDA) and superoxide dismutase (SOD) methods, respectively, and anatomy pathology diagnosis. Different types of the foods sterilized by ionizing radiation fed ad libitum to the individual Sprague Dawley rat demonstrated that such foods did not give any adverse effect on the reduction of body weight, the toxicological impact, nor anatomy-pathology examinations of the rats.展开更多
Peatland of central Kalimantan covers 2,934,660 ha and some areas are used for oil palm culture. Oil palm culture in peatland requires drainage system. Petland drainage is regarded to enhance greenhouse gases release ...Peatland of central Kalimantan covers 2,934,660 ha and some areas are used for oil palm culture. Oil palm culture in peatland requires drainage system. Petland drainage is regarded to enhance greenhouse gases release due to faster peat decomposition and reduce peat surface （subsidence） in certain time. To improve peat productivity, the in situ ameliorant materials should be applied such as biochar of oil palm bunches. The experiment was conducted in greenhouse gases laboratory using soil column method to determine effect of biochar of oil palm bunches on greenhouse gases flux in different peat agro-ecology. The peat samples were taken from central Kalimantan. The peat samples were collected using soil column with 20 cm-diameter and 50 cm in height. The 3 ~ 5 experiment was arranged using randomized block design with three replicates. The first factor treatment was peat samples with different agroecologies （below 3 years old of oil palm, above 3 years old of oil palm, and scrubs）, and the second factor treatment was rate of oil palm bunches biochar （0, l, 2, 3, 4 t.ha-1）. Without applying biochar of oil palm bunches, the CO2 flux from peat with scrub was higher than from peat with oil palm plantation. Application of oil palm bunches biochar in three peat agro-ecologies emitted CO2 lower than application of no biochar. Under peat with scrub ecology, methane flux increased with time period of incubation. Methane flux was generally higher by applying biochar of oil palm bunches in scrubs agroecology, however, application of oil palm biochar reduced methane flux from peat for oil palm plantation. The increase of rate of oil palm bunches biochar decreased significantly more GHGs emission （P 〈 0.01）.展开更多
基金supported by the Centre for Sustainable Forest Management at Forest Research Institute (FRI), Rotorua, New Zealand
文摘A study was carried out to test the effects of three rates of TSP （triple superphosphate） （0, 50, and 100 mg·kg^-1 P） on growth of broom with and without radiata pine seedlings and to determine the relationships between P concentrations in the broom shoot and dry matter yields with soil plant-available P （Bray-2 P）. A bulk sample of soil was collected from Kaweka forest at soil depth of 0-10 cm, in New Zealand on March 11, 2001. The forest area was not supplied with fertiliser at least 30 years. The results show that TSP application increased P avail- ability in the soil. The P availability concentration in soil of broom with radiata pine seedlings was higher than that in soil of broom alone. Bray-2 P concentrations had a significant logarithmic relationship with Pcon- centrations of broom shoot and an exponential relationship with dry matter weight of whole broom plant.
基金supported by Massey University and the Centre for Sustainable Forest Management at Forest Research Institute, New Zealand
文摘A study was carried out to investigate changes in the soil plant-available P,the P nutrition and the growth of Pinus radiata seedlings grown in association with understory,broom（Cytisus scoparius L.） or ryegrass（Lolium multiflorum） on Orthic Allophanic Soil,following the application of three rates of triple superphosphate（TSP）（0,50,and 100 mg·kg^-1P） under a glasshouse condition.The application of P fertilizer enhanced P availability in the rhizospheric of radiata seedlings and the bulk soils in a P-deficient site.P availability in the rhizospheric soils of ryegrass and broom,grown in association with radiata,were also increased by the presence of radiata roots.P concentrations in new shoot needles,old shoot needles,stem and roots of radiata pine increased with increase rates of TSP application,but the effects of ryegrass and broom on P nutrition of radiata seedlings depended on the soil P status.In the absence of P fertilizer addition（control treatment）,P concentrations in new shoot needles,old shoot needles,stem,and roots of radiata grown in association with broom were higher than those with ryegrass,whereas,when P fertilizer was added（50 and 100 mg·kg^-1） the P concentration was lower.This is probably related to the growth of broom that may have removed much of the plant-available P in the soil as indicated by the consistently lower Bray-2 P concentration in the rhizosphere soil of radiata in association with broom than that in the rhizosphere soil of radiata in association with grass at the two high P rates.Furthermore,in the high P fertile soil（application rate of 100 mg·kg^-1）,the dry matter yield of radiata was lower when it was grown with broom than with ryegrass.This result suggests that in moderate to high P fertile soils,P.radiata seedlings grow better with ryegrass than with broom,because broom grows vigorously in high P fertile soil and competes with P.radiata for P and perhaps for other nutrients as well.
文摘Changes in phosphorus （P） fractions in a P deficient allophanic soil under P. radiata seedlings grown with broom （Cytisus scoparius L.） and ryegrass （Lolium multiflorum） in pots were studied 14 months after the application of triple superphosphate at the rates of 0, 50, and 100 pg.g^-1, to determine the fate of fertiliser-derived P in the rhizosphere soils. Application of P fertiliser increased NaOH-Pi, NaOH-Po, and H2SO4-Pi concentrations in the soil, but decreased the residual-P concentration. The resin-Pi concentration, which is ex- tremely low in this soil （1 to μgg^-1 ）, remained the same. The majority of the added fertiliser P was however recovered in the NaOH-Pi fraction （40%-49%）. This is due to the high P fixation in this soil （92%）. The second highest P recovery was in NaOH-Po fraction （7%-19%）. Under P deficient condition or addition at the rate of 0 μg.g^-6, the NaOH-Pi concentration in the radiata rhizosphere soil was lower than that in the bulk soil and broom and grass rhizosphere soils. This may be due to higher oxalate production by the roots and mycorrhiza under P deficient conditions which released some ＆the P fixed to the soils in the rhizosphere, which needs to be tested in future studies.
基金supported by Centre for Sustainable Forest Management at Forest Research Institute, New Zealand
文摘Changes in phosphorus (P) fractions in a P deficient allophanic soil under P. radiata seedlings grown with broom (Cytisus scoparius L.) and ryegrass (Lolium multiflorum) in pots were studied 14 months after the application of triple superphosphate at the rates of 0, 50, and 100 μg·g-1, to determine the fate of fertiliser-derived P in the rhizosphere soils. Application of P fertiliser increased NaOH-Pi, NaOH-Po, and H2SO4-Pi concentrations in the soil, but decreased the residual-P concentration. The resin-Pi concentration, which is extremely low in this soil (1 to 3 μg·g-1 ), remained the same. The majority of the added fertiliser P was however recovered in the NaOH-Pi fraction (40%?49%). This is due to the high P fixation in this soil (92%). The second highest P recovery was in NaOH-Po fraction (7%?19%). Under P deficient condition or addition at the rate of 0 μg·g-1, the NaOH-Pi concentration in the radiata rhizosphere soil was lower than that in the bulk soil and broom and grass rhizosphere soils. This may be due to higher oxalate production by the roots and mycorrhiza under P deficient conditions which released some of the P fixed to the soils in the rhizosphere, which needs to be tested in future studies.
基金financially supported by Massey University and the Centre for Sustainable Forest Management at Forest Research Institute,New Zealand
文摘Silvicultural approaches at forest plantations with wider initial tree spacing have created potential for increased understory vegetation growth in response to increased light and greater nutrient resources. In conse- quence understory vegetation can fill a more important role in forest ecosystems, especially in interactions （competi- tion or facilitation） between understorey vegetation and forests trees that might affect tree growth and nutrition. Considerable research has been carried out on plant inter- ference. However, the experimental designs used in these studies vary from one study to another, and from species to species depending on the aims, objectives and practicalities of the studies. Thus there is no optimum design for com- petition experiments. This review discusses designs avail- able in studying plant interferences in a glasshouse, particularly the effects of below-ground interaction of understorey vegetation and forest trees.
文摘Development of gamma irradiated high moisture traditional dishes derived from locally traditional récipe aimed for specific target groups as ready to eat foods for ensuring the safety, quality, and security purposes have been conducted. The formation of free radicals in the traditional foods induced by ionizing radiation is a part of toxicological studies on irradiated traditional foods was to provide local scientific data base on safe- ty issues.The different foods such as steamed gold fish, spicy curry beef and soy sauces beef were individually vacuum packed in a laminate pouch of PET 12 μm/LDPE 2 μm/AL-Foil 7 μm/LDPE 2 μm/LLDPE 50 μm (PET/Al-Foil/ LLDPE), then kept at frozen state. The frozen samples were maintained in cryogenic condition along the irradiation process by placing the samples in styrofoam boxes filled with dry ice then irradiated with gamma rays at the dose of 45 kGy. The irradiated samples were kept and stored at normal temperature prior to test. Both irradiated conventional rat’s feed at normal temperature with the dose of 4 kGy and unirradiated one as control were also made. Irradiated and unirradiated samples were sent to animal laboratory, and fed into individual female Sprague Dawley rat as member of a group. The parameters observed were body weight changed of rats, toxicological test to observe the effect free radicals formation in rat’s blood by using malon-dialdehyde (MDA) and superoxide dismutase (SOD) methods, respectively, and anatomy pathology diagnosis. Different types of the foods sterilized by ionizing radiation fed ad libitum to the individual Sprague Dawley rat demonstrated that such foods did not give any adverse effect on the reduction of body weight, the toxicological impact, nor anatomy-pathology examinations of the rats.
文摘Peatland of central Kalimantan covers 2,934,660 ha and some areas are used for oil palm culture. Oil palm culture in peatland requires drainage system. Petland drainage is regarded to enhance greenhouse gases release due to faster peat decomposition and reduce peat surface （subsidence） in certain time. To improve peat productivity, the in situ ameliorant materials should be applied such as biochar of oil palm bunches. The experiment was conducted in greenhouse gases laboratory using soil column method to determine effect of biochar of oil palm bunches on greenhouse gases flux in different peat agro-ecology. The peat samples were taken from central Kalimantan. The peat samples were collected using soil column with 20 cm-diameter and 50 cm in height. The 3 ~ 5 experiment was arranged using randomized block design with three replicates. The first factor treatment was peat samples with different agroecologies （below 3 years old of oil palm, above 3 years old of oil palm, and scrubs）, and the second factor treatment was rate of oil palm bunches biochar （0, l, 2, 3, 4 t.ha-1）. Without applying biochar of oil palm bunches, the CO2 flux from peat with scrub was higher than from peat with oil palm plantation. Application of oil palm bunches biochar in three peat agro-ecologies emitted CO2 lower than application of no biochar. Under peat with scrub ecology, methane flux increased with time period of incubation. Methane flux was generally higher by applying biochar of oil palm bunches in scrubs agroecology, however, application of oil palm biochar reduced methane flux from peat for oil palm plantation. The increase of rate of oil palm bunches biochar decreased significantly more GHGs emission （P 〈 0.01）.
