| 1. |
- Kumar, Uttam
(författare)
-
Molybdenum status and critical limit in the soil for green gram (Vigna radiata) growing in Madurai and Sivagangai districts of Tamil Nadu, India
- 2013
-
Ingår i: Soil Science and Plant Nutrition. - : Informa UK Limited. - 0038-0768 .- 1747-0765. ; 59, s. 229-236
-
Tidskriftsartikel (refereegranskat)abstract
- A survey was undertaken during 2008 to determine molybdenum (Mo) status of soils and to establish critical limits in soils of Madurai and Sivagangai districts of Tamil Nadu. A total of 202 surface soil samples were collected from 16 soil series of the study areas based on their percent coverage. The samples were analyzed for extractable or available Mo. Extractable Mo varied from 0.028 to 0.661mgkg(1) and 0.035 to 0.961mgkg(1) at Madurai and Sivagangai districts, respectively. Based on the results of a pot culture experiment, the critical limit of available Mo was determined to be 0.043mgkg(1) for green gram [Vigna radiata (L.) Wilczek] (Var; CO 6) in both the districts. Based on this critical limit, we classified the soils into three categories: (1) low: <0.043mgkg(1) (2) medium: 0.0430.082mgkg(1) (3) high: >0.082mgkg(1). Green gram responded highly to Mo application in soils below the critical limit whereas soils with Mo greater than 0.082mgkg(1) did not respond. Among rates of Mo application, 0.075mgkg(1) showed better yield than others. Overall, 341% and 746% of total area in Madurai and Sivagangai districts were in the low to medium Mo status, respectively. The application of 0.075mg of Mokg(1) or 0.4kgha(1) as sodium molybdate was sufficient to optimize green gram yield in the major soil series of the districts. These results will be useful in decision-making to apply Mo for improving green gram yields in the two districts studied.
|
|
| 2. |
- Martinsen, V., et al.
(författare)
-
pH effects of the addition of three biochars to acidic Indonesian mineral soils
- 2015
-
Ingår i: Soil science and plant nutrition (Tokyo). - : Informa UK Limited. - 0038-0768 .- 1747-0765. ; 61:5, s. 821-834
-
Tidskriftsartikel (refereegranskat)abstract
- Soil acidity may severely reduce crop production. Biochar (BC) may increase soil pH and cation exchange capacity (CEC) but reported effects differ substantially. In a systematic approach, using a standardized protocol on a uniquely large number set of 31 acidic soils, we quantified the effect of increasing amounts (0-30%; weight:weight) of three types of field-produced BCs (from cacao (Theobroma cacao. L.) shell, oil palm (Elaeis guineensis. Jacq.) shell and rice (Oryza sativa. L.) husk) on soil pH and CEC. Soils were sampled from croplands at Java, Sumatra and Kalimantan, Indonesia. All BCs caused a significant increase in mean soil pH with a stronger response and a greater maximum increase for the cacao shell BC addition, due to a greater acid neutralizing capacity (ANC) and larger amounts of extractable base cations. At 1% BC addition, corresponding to about 30tonsha(-1), the estimated increase in soil pH from the initial mean pH of 4.7 was about 0.5 units for the cacao shell BC, whereas this was only 0.05 and 0.04 units for the oil palm shell and rice husk BC, respectively. Besides depending on BC type, the increase in soil pH upon the addition of each of the three BCs was mainly dependent on soil CEC (low CEC resulting in stronger pH increase), and to a lesser extent on initial soil pH (higher initial pH resulting in stronger pH increase). Addition of BC also increased the amount of exchangeable base cations (cacao shell >> oil palm and rice husk) and CEC. Through this systematic screening of the effect of BC on pH and CEC of acidic soils, we show that a small addition of BC, in particular if made of cacao shell, to acidic agricultural soils increases soil pH and CEC. However, the response is highly dependent on the type, quality and amount of the added BC as well as on intrinsic soil properties, mainly CEC.
|
|
| 3. |
- Parvage, Masud, et al.
(författare)
-
Effect of mouldboard ploughing and shallow tillage on sub-soil physical properties and crop performance
- 2014
-
Ingår i: Soil Science and Plant Nutrition. - : Informa UK Limited. - 0038-0768 .- 1747-0765. ; 60, s. 38-44
-
Tidskriftsartikel (refereegranskat)abstract
- This study was conducted in spring 2011 in a long-term field experiment with the objective of assessing the effect of shallow tillage (ST) and mouldboard ploughing (MP) on important soil physical properties and crop performance. Undisturbed soil samples were taken before sowing from depths of 15-20, 25-30 and 35-40cm for the determination of saturated hydraulic conductivity (Ks), bulk density (Bd), and water retention capacity in laboratory conditions. Penetrometer resistance (PR) was measured in the field after 1 month of sowing. Plant density of barley (Hordeum vulgare) was also counted after 1 month of sowing. Field water content was significantly higher for MP than ST at 15-20cm (MP=27%, ST=22.5%) and 25-30cm depth (MP=29.3%, ST=24.8). Water retention at 1 m suction was also significantly higher in the treatment with MP at the depth of 25-30cm (31%) than in the ST treatment (27.7%). Significantly higher Ks value was found for ST at depths of 15-20 (13.09cm h(-1)) and 25-30cm (5.10cm h(-1)) than for MP (11.15 and 3.52cm h(-1), respectively). Soil Bd was significantly lower in MP treatments for the first two investigated depths (1.43 and 1.44gcm(-3), respectively) than in the ST (1.54 and 1.53gcm(-3)). Significant higher PR value was found for ST, especially at the depth of 5-35cm, but the result was not so high as to reduce the root growth. Water content determined parallel with PR measurement was not significantly different for the two treatments. Plant density as well as crop yield in the ST treatment was higher (3840kgha(-1)) than in the MP treatment (2490kgha(-1)). Therefore, we concluded that long-term ST treatment markedly influenced crop performance and yield by facilitating soil physical properties.
|
|
