A common crop rotation in the west Iran is wheat-fallow-corn. The fallow period after wheat harvest (during fall and winter) can lead to soil erosion, nutrient losses (e.g. nitrate leaching) and offsite movement of pe...A common crop rotation in the west Iran is wheat-fallow-corn. The fallow period after wheat harvest (during fall and winter) can lead to soil erosion, nutrient losses (e.g. nitrate leaching) and offsite movement of pesticides. This period is an ideal time to establish a cover crop. In order to investigate the effects of different autumn-seeded cover crops on subsequent irrigated corn response to nitrogen fertilizer, field studies were carried out during the 2007-2008 growing season at the Agricultural Research Farm, Razi University, Kermanshah, Iran. The experiment was conducted in a split plot arrangement based on a randomized complete block design with three replications. The main plots consisted of four cover crops including alfalfa (Medicago sativa L.), berseem clover (Trifolium alexandrinum L.), common vetch (Vicia sativa L.) and winter rye (Secale cereale L.) and a control (no cover crop). The sub plots consisted of two fertilizer N rates (0 and 250 kg ha-1). Cover crops were grown for nearly 5 months and then were incorporated into the soil as green manures. The results indicated that corn plant traits including seed yield, the number of seeds per ear and leaf chlorophyll content were significantly influenced by cover crops. Whereas, the cover crops had no signif-icant effects on the number of ears per plant, 100-seed weight and harvest index of corn. Among the cover crop species, common vetch produced higher dry weight and showed the highest positive effects on the corn plant traits. Dry weight produced by this cover crop was 56.41, 120.16 and 124.19% higher than those of winter rye, berseem clover and alfalfa, respectively. Common vetch enhanced seed yield, the number of seeds per ear and leaf chlorophyll content of corn by 46.30, 21.95 and 8.52%, respectively, compared to control. All of the corn traits under study, except the number of ears per plant and harvest index were significantly improved by nitrogen fertilizer. In general, this study revealed that the autumn-seeded cover crops, especially common vetch can be used to improve corn yield. However, the cover crops should be supplemented with nitrogen fertilizer to obtain optimal results.展开更多
[ Objective ] The paper was to investigate the content of 1,2-propanediol in silage feed. [ Method ] Whole-crop corn was stored in laboratory bag silos and outdoor bunker silos. Bag silos were stored for 3, 7, 14, 28,...[ Objective ] The paper was to investigate the content of 1,2-propanediol in silage feed. [ Method ] Whole-crop corn was stored in laboratory bag silos and outdoor bunker silos. Bag silos were stored for 3, 7, 14, 28, 56 and 120 d, respectively, and fermentation products were analyzed after opening; the fermentation products, which were from three 500 t above-ground outdoor bunker silos stored for 120 d, were detected. Eight sampling points were selected for each bunker silo. [ Result] No 1,2-propanediol was detected out in laboratory bag silos, and lactic acid was dominant in fermentation products. The acetic acid content significantly increased （ P 〈 0.05 ） with the extension of storage time, whereas the acetic acid content was kept below one-third of the lactic acid content ; 1,2-propanediol and a small amount of 1-propanol were detected out in three bunker silos, and lactic acid was dominant in fermentation products, whereas the content of acetic acid was slightly lower than that of lactic acid. The differences in fermentation products from different silos and different sites in silos presented heterogeneity; except to propanediol, lactic acid bacteria and yeast, there was no significant difference in fermentation products at the top and bottom layers of silos （ P 〉0.05 ） ; there were significant differences in contents of lactic acid, acetic acid, 1,2-propanediol, and yeast between the outer and inner parts of silos （P 〈 0.05 ） ; except to pH values and acetic acid, there were significant differences in fermentation products between hunker silos （P 〈0. 05）. [ Conclusion] No 1,2-propanediol is detected out in laboratory bag silos due to relatively simple fermentation products. However, 1,2-propanediol can be detected in the bunker silos due to complex outdoor environment for silage, and the microorganisms producing 1,2-propanediol exist in silos.展开更多
In this paper, the concentration distribution and environmental fate of atrazine in a crop soil groundwater system at Baiyangdian Lake area of North China were studied. The concentration of the herbicide in spatial...In this paper, the concentration distribution and environmental fate of atrazine in a crop soil groundwater system at Baiyangdian Lake area of North China were studied. The concentration of the herbicide in spatial and vertical soils, and in roots, stem, leaf, corncob and kernel of corn, and in groundwater were measured by HPLC. The results showed that the variation of spatial concentration of atrazine in soil can be described by first order kinetics equation which has a half life of 360 days and a rate constant of 0.0019d -1 . The vertical variation of atrazine concentration with soil depth follows the exponential decay law. After 120 days following atrazine application, the mass distributions of this herbicide in crop soil groundwater system are 71% in soil, 20% in groundwater and 1% in crop respectively, and 8% due to loss by degradation or often removal processes. The order of atrazine concentration in every part of corn crop is in roots>in corncob>in kernel of corn>in leaf.展开更多
Field trials on the management of soil biological fertility with aim to increasing corn production were conducted in a savannah region of the DR-Congo. Three organic matters including fresh biomass of Entada abyssinic...Field trials on the management of soil biological fertility with aim to increasing corn production were conducted in a savannah region of the DR-Congo. Three organic matters including fresh biomass of Entada abyssinica, Tithonia diversifolia, Stylosanthes gracilis and a mineral combination of nitrogen and phosphorus (NP) (115-63-0) along with a control (without fertilization) were evaluated for corn crop growth and production. The field trial was a completely randomized design with four replicates. Plant height, basal stem diameter, and yield components were assessed. Irrespective of fertilization treatments and variety, maize showed a similar growth up to 20 days after sowing (DAS), and then two distinct trends were observed. At 60 DAS, plant height and basal diameter were significantly bigger in plots treated with NP, T. diversifolia and E. abyssinica compared to S. gracilis treatment and control (NoF). This pattern was also confirmed with agronomic traits such as cob length, number of kernel per cob, and net grain yield. The local variety was the least productive under any treatment. In general, the response of corn crop to organic and inorganic fertilization showed that the mineral combination (NP) increased the most grain yield and other yield components compared to unfertilized trial, followed by T. divessifolia and E. abyssinica. NP and T. diversifolia treatments increased significantly and equally soil potassium content compared to control and other treatments. Application of T. diversifolia appears a more cost effective approach for small farmers to improving fertility of the oxisol prevailing in Central Africa compared to mineral fertilizers.展开更多
A treatment based on the acetogenin fraction of the methanol extract of Rollinia occidentalis seeds was applied to soybean crops for three consecutive years. In relation to the control population, the treatment reduce...A treatment based on the acetogenin fraction of the methanol extract of Rollinia occidentalis seeds was applied to soybean crops for three consecutive years. In relation to the control population, the treatment reduced the population of Anticarsia gemmatalis, Rachiplusia nu, Pseudoplusia includens, Loxostege bifidalis and Spodoptera frugiperda to 52% and 65% after 48 h of application at concentrations of 500 and 750 μg/mL respectively, while low toxic effects were detected on natural enemies. The extract treatment at 500 μg/mL and a solution of the annonaceous acetogenin, squamocin, at 50 and 100 μg/mL, were also applied to a corn field to produce 75%, 93% and 100% mortality rates on the population of S. frugiperda, respectively, after 72 h of application. In addition, damages caused by lepidopterans in treated crops were lower than those observed in non treated fields, evaluated by residual biomass. This statement is based on data from trials with the commercially available insecticides lufenuron and cypermethrin.展开更多
The use of pig compost (PC) in agricultural land has increased in Chile in the last years. This organic amendment is a valuable nutritional source for crops, but its applying must be done in a controlled manner since ...The use of pig compost (PC) in agricultural land has increased in Chile in the last years. This organic amendment is a valuable nutritional source for crops, but its applying must be done in a controlled manner since it exhibited high copper (Cu) and zinc (Zn) concentrations. A short-term field experiment was conducted out to study the effects of increasing PC rates on the production and quality corn crop in two soils located at south central Chile. Five treatments were evaluated: control without fertilization (C), conventional fertilization (CF) (350 kg N ha-1), and three increasing PC rates (15.33, 30.65, and 61.31 Mg·ha-1, corresponding to 350, 700, and 1400 kg N ha-1, respectively) in a split plot design with four replicates. The overall results indicated that dry matter production, grain yield, and plant Zn and Cu concentrations were similar among fertilization sources and rates. Extractable soil Zn concentration exhibited a rate-related increase of PC in both locations, while Cu concentration exhibited this behavior only at the soil located in Chillan. Nevertheless, the values obtained were below of those considered phytotoxic levels. Therefore, the contribution of Zn and Cu through PC applying at different rates to the soils studied showed a slight affect in soil extractable Zn and Cu values without negatively effects on quantity and quality corn crop. The organic amendment applied can be a good and cheaper substitute to conventional fertilization, although further monitoring of Zn and Cu soil levels should be carried out to avoid any environmental risk.展开更多
文摘A common crop rotation in the west Iran is wheat-fallow-corn. The fallow period after wheat harvest (during fall and winter) can lead to soil erosion, nutrient losses (e.g. nitrate leaching) and offsite movement of pesticides. This period is an ideal time to establish a cover crop. In order to investigate the effects of different autumn-seeded cover crops on subsequent irrigated corn response to nitrogen fertilizer, field studies were carried out during the 2007-2008 growing season at the Agricultural Research Farm, Razi University, Kermanshah, Iran. The experiment was conducted in a split plot arrangement based on a randomized complete block design with three replications. The main plots consisted of four cover crops including alfalfa (Medicago sativa L.), berseem clover (Trifolium alexandrinum L.), common vetch (Vicia sativa L.) and winter rye (Secale cereale L.) and a control (no cover crop). The sub plots consisted of two fertilizer N rates (0 and 250 kg ha-1). Cover crops were grown for nearly 5 months and then were incorporated into the soil as green manures. The results indicated that corn plant traits including seed yield, the number of seeds per ear and leaf chlorophyll content were significantly influenced by cover crops. Whereas, the cover crops had no signif-icant effects on the number of ears per plant, 100-seed weight and harvest index of corn. Among the cover crop species, common vetch produced higher dry weight and showed the highest positive effects on the corn plant traits. Dry weight produced by this cover crop was 56.41, 120.16 and 124.19% higher than those of winter rye, berseem clover and alfalfa, respectively. Common vetch enhanced seed yield, the number of seeds per ear and leaf chlorophyll content of corn by 46.30, 21.95 and 8.52%, respectively, compared to control. All of the corn traits under study, except the number of ears per plant and harvest index were significantly improved by nitrogen fertilizer. In general, this study revealed that the autumn-seeded cover crops, especially common vetch can be used to improve corn yield. However, the cover crops should be supplemented with nitrogen fertilizer to obtain optimal results.
基金Supported by National Natural Science Foundation of China(31402136)Research Project of Bureau of Reclamation in Heilongjiang Province(HNK135-04-02-03)+1 种基金Postdoctoral Fund in Heilongjiang Province(LBH-Z14029)Doctoral Fund in Heilongjiang Bayi Agricultural University(B2012-06)
文摘[ Objective ] The paper was to investigate the content of 1,2-propanediol in silage feed. [ Method ] Whole-crop corn was stored in laboratory bag silos and outdoor bunker silos. Bag silos were stored for 3, 7, 14, 28, 56 and 120 d, respectively, and fermentation products were analyzed after opening; the fermentation products, which were from three 500 t above-ground outdoor bunker silos stored for 120 d, were detected. Eight sampling points were selected for each bunker silo. [ Result] No 1,2-propanediol was detected out in laboratory bag silos, and lactic acid was dominant in fermentation products. The acetic acid content significantly increased （ P 〈 0.05 ） with the extension of storage time, whereas the acetic acid content was kept below one-third of the lactic acid content ; 1,2-propanediol and a small amount of 1-propanol were detected out in three bunker silos, and lactic acid was dominant in fermentation products, whereas the content of acetic acid was slightly lower than that of lactic acid. The differences in fermentation products from different silos and different sites in silos presented heterogeneity; except to propanediol, lactic acid bacteria and yeast, there was no significant difference in fermentation products at the top and bottom layers of silos （ P 〉0.05 ） ; there were significant differences in contents of lactic acid, acetic acid, 1,2-propanediol, and yeast between the outer and inner parts of silos （P 〈 0.05 ） ; except to pH values and acetic acid, there were significant differences in fermentation products between hunker silos （P 〈0. 05）. [ Conclusion] No 1,2-propanediol is detected out in laboratory bag silos due to relatively simple fermentation products. However, 1,2-propanediol can be detected in the bunker silos due to complex outdoor environment for silage, and the microorganisms producing 1,2-propanediol exist in silos.
基金The National Natural Science Foundation of China(No.29777026)the Major Project Foundation of the Chinese Academy of Sciences(KZ951-B1-209-01)
文摘In this paper, the concentration distribution and environmental fate of atrazine in a crop soil groundwater system at Baiyangdian Lake area of North China were studied. The concentration of the herbicide in spatial and vertical soils, and in roots, stem, leaf, corncob and kernel of corn, and in groundwater were measured by HPLC. The results showed that the variation of spatial concentration of atrazine in soil can be described by first order kinetics equation which has a half life of 360 days and a rate constant of 0.0019d -1 . The vertical variation of atrazine concentration with soil depth follows the exponential decay law. After 120 days following atrazine application, the mass distributions of this herbicide in crop soil groundwater system are 71% in soil, 20% in groundwater and 1% in crop respectively, and 8% due to loss by degradation or often removal processes. The order of atrazine concentration in every part of corn crop is in roots>in corncob>in kernel of corn>in leaf.
文摘Field trials on the management of soil biological fertility with aim to increasing corn production were conducted in a savannah region of the DR-Congo. Three organic matters including fresh biomass of Entada abyssinica, Tithonia diversifolia, Stylosanthes gracilis and a mineral combination of nitrogen and phosphorus (NP) (115-63-0) along with a control (without fertilization) were evaluated for corn crop growth and production. The field trial was a completely randomized design with four replicates. Plant height, basal stem diameter, and yield components were assessed. Irrespective of fertilization treatments and variety, maize showed a similar growth up to 20 days after sowing (DAS), and then two distinct trends were observed. At 60 DAS, plant height and basal diameter were significantly bigger in plots treated with NP, T. diversifolia and E. abyssinica compared to S. gracilis treatment and control (NoF). This pattern was also confirmed with agronomic traits such as cob length, number of kernel per cob, and net grain yield. The local variety was the least productive under any treatment. In general, the response of corn crop to organic and inorganic fertilization showed that the mineral combination (NP) increased the most grain yield and other yield components compared to unfertilized trial, followed by T. divessifolia and E. abyssinica. NP and T. diversifolia treatments increased significantly and equally soil potassium content compared to control and other treatments. Application of T. diversifolia appears a more cost effective approach for small farmers to improving fertility of the oxisol prevailing in Central Africa compared to mineral fertilizers.
文摘A treatment based on the acetogenin fraction of the methanol extract of Rollinia occidentalis seeds was applied to soybean crops for three consecutive years. In relation to the control population, the treatment reduced the population of Anticarsia gemmatalis, Rachiplusia nu, Pseudoplusia includens, Loxostege bifidalis and Spodoptera frugiperda to 52% and 65% after 48 h of application at concentrations of 500 and 750 μg/mL respectively, while low toxic effects were detected on natural enemies. The extract treatment at 500 μg/mL and a solution of the annonaceous acetogenin, squamocin, at 50 and 100 μg/mL, were also applied to a corn field to produce 75%, 93% and 100% mortality rates on the population of S. frugiperda, respectively, after 72 h of application. In addition, damages caused by lepidopterans in treated crops were lower than those observed in non treated fields, evaluated by residual biomass. This statement is based on data from trials with the commercially available insecticides lufenuron and cypermethrin.
文摘The use of pig compost (PC) in agricultural land has increased in Chile in the last years. This organic amendment is a valuable nutritional source for crops, but its applying must be done in a controlled manner since it exhibited high copper (Cu) and zinc (Zn) concentrations. A short-term field experiment was conducted out to study the effects of increasing PC rates on the production and quality corn crop in two soils located at south central Chile. Five treatments were evaluated: control without fertilization (C), conventional fertilization (CF) (350 kg N ha-1), and three increasing PC rates (15.33, 30.65, and 61.31 Mg·ha-1, corresponding to 350, 700, and 1400 kg N ha-1, respectively) in a split plot design with four replicates. The overall results indicated that dry matter production, grain yield, and plant Zn and Cu concentrations were similar among fertilization sources and rates. Extractable soil Zn concentration exhibited a rate-related increase of PC in both locations, while Cu concentration exhibited this behavior only at the soil located in Chillan. Nevertheless, the values obtained were below of those considered phytotoxic levels. Therefore, the contribution of Zn and Cu through PC applying at different rates to the soils studied showed a slight affect in soil extractable Zn and Cu values without negatively effects on quantity and quality corn crop. The organic amendment applied can be a good and cheaper substitute to conventional fertilization, although further monitoring of Zn and Cu soil levels should be carried out to avoid any environmental risk.
