• Authors:
    • Diaz-Zorita, M.
    • Pena-Yewtukhiw, E.
    • Grove, J.
    • Blevins, R.
  • Source: Better Crops with Plant Food
  • Volume: 93
  • Issue: 4
  • Year: 2009
  • Summary: This long-term Kentucky study evaluated the impact of tillage and N rates on crop yield and soil organic matter (SOM). After 29 years of continuous corn with a winter cereal cover crop, the combination of no-till cropping and fertilizer N use resulted in SOM levels similar to those in adjacent grass sod. There was no evidence that fertilizer N caused SOM loss.
  • Authors:
    • Raina, S.
    • Jaggi, R.
  • Source: Indian Journal of Fertilisers
  • Volume: 5
  • Issue: 2
  • Year: 2009
  • Summary: Nitrogen application up to 240 kg/ha consistently increased total and large-sized potato tuber yield over no N. However, higher levels of N led to the deterioration in nutritional, processing and storage quality of potato. Applying 75% of N as basal and 25% as top dressing improved the storage quality of potato. The effect of FYM was more pronounced in the absence of N. Use of biofertilizers in conjunction with organic fertilizers increased their efficiency and served as a supplementing source to increase nutrient availability for sustainable agriculture especially in heavy feeder crop like potato. This also reduced P dose without sacrificing yield and kept soil healthier at the same time. The optimum doses of K for mid hill soils of Himachal Pradesh were worked out to be 62 to 112 kg/ha with and without FYM, respectively. Significant improvement in storability of potato was observed up to 100 kg K 2O/ha. A significant response to application of micronutrients (Zn, Mn and Fe) was observed under Jammu and Himachal Pradesh soils. There was also a significant response to seed rate, sowing time and irrigation. Intercrops of cabbage, french bean and pea with potato were very productive and far more remunerative than sole potato. There was a good response to balanced and integrated nutrient management in potato.
  • Authors:
    • Zorza, E.
    • Perez, L.
    • Perez, M.
    • Rainero, H.
    • Rodriguez, N.
    • Leguizamon, E.
    • Fernandez-Quintanilla, C.
  • Source: Weed Research
  • Volume: 49
  • Issue: 1
  • Year: 2009
  • Summary: Field trials were established in various growing seasons in four experimental sites with soyabeans or maize grown under no tillage systems. Seeds of Digitaria sanguinalis, Eleusine indica, Sorghum halepense, Setaria geniculata, Echinochloa colonum and Urochloa platyphylla were incorporated in surface soil, under the crop residues of the previous season, each autumn. Regular records of seedling emergence during the following spring and summer were used to model the pattern of each species as a function of the thermal time in the 2 cm upper layer of the soil profile. A Weibull function closely described ( r2=0.73-0.93) the relationship between thermal time and seedling emergence for all species in each site and year. The coefficient of determination for the model verification ranged from 0.71 to 0.98. Species may be grouped into three emergence time-span groups. Eleusine indica, U. platyphylla and E. colonum had a long-lasting emergence, requiring 940-1660 ddegreesC (growing day degrees) to complete this process. Digitaria sanguinalis and S. halepense had an intermediate emergence time-span, completing this process in 540-1090 ddegreesC. Setaria geniculata exhibited the shortest emergence time-span (290-660 ddegreesC required for full emergence). Different hypotheses were tested in order to explain species model parameter differences in different sites and to establish the basis for more refined models with improved prediction capabilities.
  • Authors:
    • Xu, Z.
    • Cao, Z.
    • Chen, Y.
    • Liang, X.
    • Li, H.
    • Li, S.
  • Source: Journal of Soils and Sediments
  • Volume: 9
  • Issue: 5
  • Year: 2009
  • Summary: Background, aim, and scope - A large area of water eutrophication in the Tai Lake region of China was associated with nitrogen (N) and phosphorus (P) pollution, mainly due to the discharge of untreated rural wastewater (RW) into the surface water (SW) near villages of this region. A field experiment was conducted, using irrigation of RW plus urea fertilization under equal nitrogen (N) rate, namely, black water (BW), domestic wastewater (DW), gray water (GW), SW, and SW without any N application as a control (CK), to elucidate N removal by the paddy wetland system during the rice growing season of 2007. Materials and methods - SW, GW, DW, and BW were collected from the village of Liangzhu in subtropical China. Water samples were stored in darkness at 4°C in an icebox prior to analysis. Total nitrogen (TN) was analyzed by the spectrophotometric method with a continuous-flow automated analyzer. For the soil analyses, pH was measured using a pH meter with soil/distilled water=1:5; cation exchange capacity was determined with an unbuffered salt extraction method. Redox potential (Eh) was obtained using a pH meter with a platinum electrode, whereas organic carbon (C) was determined using the Walkley and Black method. TN was calculated by acid-alkali neutralization, after the soil samples were digested with concentrated sulfuric acid (H 2SO 4), distilled and then absorbed by diluted boric acid (H 3BO 3), and available N was determined by alkaline-proliferation law, after the samples were hydrolyzed, reduced, and absorbed by H 3BO 3. Available P was determined with the colorimetric method at the wave length of 660 nm, after the samples were extracted with NaHCO 3, and available K was extracted by unbuffered NH 4Cl and then determined by the atomic absorption spectrophotometer. The rice plant samples were digested with H 2SO 4-H 2O 2, and N contents were analyzed by the atomic absorption spectrophotometry. Results - Yield for the CK was significantly less ( P≤0.05) than those of SW, GW, DW, and BW, with the yield of BW significantly greater ( P≤0.05) than all the other treatments. The TN concentration of the floodwater in the paddy wetland system decreased rapidly after transplanting, rose significantly ( P≤0.05) after two N topdressings, and then decreased gradually as the following sequences: SW > GW > DW > BW > CK, but tended to be stable until 15 October. Meanwhile, TN removal rates from the wastewater were significantly higher ( P≤0.05) than those from the urea fertilizer. Total N load (TNL) increased significantly after two topdressings and reached the maximum value just after the first topdressing on 22 July: SW, 21.0 kg ha -1; GW, 19.1 kg ha -1; BW, 15.3 kg ha -1; DW, 14.3 kg ha -1; and CK, 0.57 kg ha -1. Subsequently, TNL declined gradually and reached stability on 15 October. Just after the rice seedlings were transplanted, the soil released a large amount of inorganic N (26.3%-40.4%); however, after the topdressing, the soil adsorbed a lot of N and TNL originating from the RW, which had decreased, ranging from 34.5% to 47.8%. Discussion - A reasonable N rate would be necessary for normal rice production in the Tai Lake region, which is different from those studies of other systems. Irrigation with RW for the paddy field could not only reduce the amount of commercial N fertilizer usage and irrigation water but also increase rice grain yield. Meanwhile, N use efficiency was improved by the combination of both N fertilizer and RW. The more N fertilizer was used, the higher the TN concentration in the flooded water would be, and the more potential risk of N to the surface water body. However, the N in RW could be removed more easily than that of the fertilizer by the paddy wetland system, which may be related to the existing form and concentration of N in the RW and urea fertilizer. The TNL in the floodwater had a positive correlation with the urea application rate, implying that appreciable amounts of N input might be lost, either by a heavy rainfall event or floodwater drainage using improper water management methods closely subsequent to the urea application. This revealed that using GW, DW, or BW instead of SW as irrigation water could decrease the loss of N applied and reduce the environmental pollution risk for the surface water. Conclusions - Supplemental N was necessary in this area for normal rice production, and the rice grain yield of CK (without any N fertilizer applied) was significantly lower than the other treatments; however, the yield of SW (with N fertilizer applied) was not significantly different from those of GW and DW. However, irrigation with RW in the paddy rice field could reduce costs of fertilizer and irrigation water. In addition, using BW would significantly increase rice yield revenues. The paddy wetland system also removed large quantities of N due to the irrigation with RW and applied N fertilizer, with the TN removal rates for RW significantly higher than that for the N fertilizer. Thus, application of RW instead of N fertilizer alone could greatly decrease the discharge of N into water bodies; thus, paddy wetland system can be considered as a new method for the RW treatment, especially in the Tai Lake region of China. Recommendations and perspectives - Based on this study, it would be strongly recommended to use RW irrigation after it had been disinfected for reducing part of commercial N fertilizer rate and saving some irrigation water in rice production with the paddy wetland system as a cost-effective way to remove the N from the RW and mitigate the non-point pollution. Future work should pay attention to the largest N-removal capacity of the paddy wetland system per unit and the effect on the rice grain quality irrigated with the RW.
  • Authors:
    • Nakagawa, J.
    • Cavariani, C.
    • Crusciol, C.
    • Lima, E.
  • Source: Revista Brasileira de Sementes
  • Volume: 31
  • Issue: 1
  • Year: 2009
  • Summary: Soybean productivity under the no till system (NTS) can be influenced by the preceding type of plant cover and surface liming. However, the effects of this technique on yield components and the seed physiological quality have been little studied, especially in ("safrinha") off-season soybean under NTS. Therefore, this study aimed to evaluate some agronomic traits, yield components, productivity, and physiological quality of soybean grown during the off-season ("safrinha"), as a function of different cover plants, with or without surface liming, under NTS. The experiment was conducted during the 1999/00 cropping season on the Lageado Experimental Farm, FCA/UNESP/Botucatu-SP, Brazil. The experimental design was organized as randomized blocks in split-plots, with 4 replications. The 6 m * 10 m plots consisted of broomcorn ( Sorghum bicolor), millet ( Pennisetum americanum), fall panicum ( Panicum dichotomiflorum), spontaneous vegetation, and no vegetation. At 53 days after emergence the cover plants were desiccated and lodged, and a surface application of 3.1 t.ha-1 lime was made in half of the plots, in order to increase V% to 70. Soybean (cv. IAC-19) was sown two weeks later, during the off-season ("safrinha"). Determinations were made for the final stand, first pod height, plant height, total number of pods and blank pods per plant, total number of seeds per pod, 100-seed weight and yield. As to seed physiological quality, determinations were made for germination, artificial aging, germination at 18C, plantlet D.M., and electric conductivity. During NTS implementation, plant cover type and surface liming did not affect the agronomic traits studied, yield components, seed productivity, and physiological quality of soybean seeds grown in the off-season ("safrinha") system, except for electric conductivity.
  • Authors:
    • Sudhakar, S.
    • Ashish, P.
    • Panda, S.
    • Pandey, V.
  • Source: Environmental Geology
  • Volume: 56
  • Issue: 5
  • Year: 2009
  • Summary: An effort was made to identify the critical sub-watersheds for the development of best management plan for a small watershed of Eastern India using a hydrological model, namely, AVSWAT2000. A total of 180 combinations of various management treatments including crops (rice, maize, groundnut and soyabean), tillage (zero, conservation, field cultivator, mouldboard plough and conventional practices) and fertilizer levels (existing half of recommended and recommended) have been evaluated. The investigation revealed that rice cannot be replaced by other crops such as groundnut, maize, mung bean, sorghum and soyabean since comparatively these crops resulted in higher sediment yield. The tillage practices with disc plough have been found to have more impact on sediment yield and nutrient losses than conventional tillage practices for the existing level of fertilizer. Sediment yield decreased in the case of zero tillage, conservation tillage, field cultivator, mouldboard plough, and conservation tillage as compare to conventional tillage. Lowest NO 3-N loss was observed in zero tillage in all the fertilizer treatments, whereas field cultivator, mouldboard plough and disc plough resulted in increase of NO 3-N loss. As compared to conventional tillage, the losses of soluble phosphorus were increased in mouldboard plough. The losses of organic nitrogen were also increased as fertilizer dose increased. After zero tillage the conservation tillage performed better in all the fertilizer treatments as per loss of organic nitrogen and organic phosphorus is concerned. It can be concluded that the sediment yield was found to be the highest in the case of disc plough followed by mouldboard plough, field cultivator, conventional tillage, field cultivator and least in zero tillage practices. The nutrient losses were found to be in different order with tillage practices, resulted highest in disc plough tillage practices. In view of sediment yield and nutrient losses, the conservation tillage practice was found to be the best as the sediment yield is less than the average soil loss whereas nutrient loss is within the permissible limit.
  • Authors:
    • Singh, O.
    • Sandeep, S.
  • Source: International Journal of Agricultural Sciences
  • Volume: 5
  • Issue: 1
  • Year: 2009
  • Summary: A field experiment was conducted during winter season of 2003-04 and 2004-05 at J.V.P.G. College, Baraut (Bagpat) in western Uttar Pradesh to study the optimum dose of nitrogen for component crop in the sole french bean ( Phaseolus vulgaris Linn.) and patato ( Solanum tubersum L.) and in intercropping system. Frenchbean and Potato yields increased significantly upto the application of 120 Kg N and 60 Kg K 2O/ha. Frenchbean equivalent yield was highest of 31.90 q/ha at 120 kg N/ha and 29.63 q/ha which were found 2.28 q/ha (7.9%) and 6.88 q/ha (28.2%) higher than the equivalent yield in sole potato and sole frenchbean, respectively. Intercropping attained 1.17 L.E.R. which indicates that land may be utilized by 17 per cent more than pure cropping.
  • Authors:
    • Singh, K.
    • Nandita, G.
    • Alka, S.
    • Ritu, M.
    • Sonu, S.
  • Source: Soil Science Society of America Journal
  • Volume: 73
  • Issue: 5
  • Year: 2009
  • Summary: The application of organic amendments in agroecosystems has been widely recommended, but the impact of their C/N ratio on the stabilization and sequestration of soil organic carbon (SOC) is often unaccounted for. The influence of the C/N ratio of amendments on soil physicochemical properties in a rice ( Oryza sativa var. NDR97)-barley ( Hordeum vulgare var. Lakhan) rotation tropical dryland agroecosystem was compared with an undisturbed grassland. Chemical fertilizer in the form of urea and three organic inputs ( Sesbania aculeata shoot, low C/N ratio; air-dried straw of wheat ( Triticum aestivum var. Malviya 533), high C/N ratio; and S. aculeata shoot+wheat straw, high and low C/N ratio combined) carrying an equivalent amount of N, were added to plots of the agroecosystem once during each annual cycle. Soil water-holding capacity (WHC), porosity, SOC, total N, and aggregate stability were improved in the wheat straw and S. aculeata shoot+wheat straw treatments, reaching levels comparable with the grassland. Soil WHC, porosity, and SOC influenced the productivity of the grassland and the agroecosystem. The grassland recorded highest SOC (53% higher relative to control) followed by the wheat straw (+47%), S. aculeata shoot+wheat straw (+37%) and soil total N was greatest in the S. aculeata shoot+wheat straw treatment (+37.5%). Aggregate stability and macroaggregate distribution were also higher in the wheat straw and S. aculeata shoot+wheat straw treatments, however, the microaggregate and silt+clay fractions showed a reverse trend. Management practices with a higher residue-C return in the agroecosystem resulted in increased aggregate stability and aggregate-associated SOC, with C storage attaining levels similar to the natural system.
  • Authors:
    • Mikha, M.
    • Vigil, M.
    • Lyon, D.
    • Schlegel, A.
    • Stone, L.
    • Blanco-Canqui, H.
    • Stahlman, P.
    • Rice, C.
  • Source: Soil Science Society of America Journal
  • Volume: 73
  • Issue: 6
  • Year: 2009
  • Summary: Compaction can be a problem in some no-till (NT) soils, but accumulation of soil organic C (SOC) with time may reduce the soil's susceptibility to compaction. Relationships between SOC and soil maximum bulk density (BD max), equivalent to maximum soil compactibility, have not been well documented, particularly in NT systems. We assessed near-surface BD max using the Proctor test under long-term (>19 yr) moldboard plow (MP), conventional tillage (CT), reduced tillage (RT), and NT conditions in the central Great Plains and determined its relationships with SOC, particle size distribution, and Atterberg consistency limits. The experiments were located on silt loam soils at Hays and Tribune, KS, and loam soils at Akron, CO, and Sidney, NE. The near-surface BD max of the MP soil was higher than that of the NT soil by 13% at Sidney, while the near-surface BD max of the CT was higher than that of the NT soil by about 6% at Akron, Hays, and Tribune. Critical water content (CWC) for BD max in the NT soil was higher than in the CT and MP soils except at Tribune. The BD max decreased with increase in CWC ( r=-0.91). The soil liquid limit was higher for NT than for MP by 82% at Sidney, and it was higher than for CT by 14, 9, and 31% at Akron, Hays, and Tribune, respectively. The SOC concentration in NT soil was higher than in MP by 60% at Akron and 76% at Sidney, and it was higher than in CT soil by 82% at Hays. The BD max decreased ( r=-0.64) and the CWC increased ( r=0.60) with an increase in SOC concentration. Across all soils, SOC concentration was a sensitive predictor of BD max and CWC. This regional study showed that NT management-induced increase in SOC improves the soil's ability to resist compaction.
  • Authors:
    • Bergtold, J. S.
    • Raper, R. L.
    • Price, A. J.
    • Kornecki, T. S.
  • Source: Applied Engineering in Agriculture
  • Volume: 25
  • Issue: 6
  • Year: 2009
  • Summary: In a weed-free field with ideal weather conditions, a cash crop can be planted 3 weeks after rolling a mature cereal rye winter cover crop without using herbicides. However, cloudy and wet weather can delay the rolling and/or desiccation of rye, thereby delaying cash crop planting which can negatively impact yield. One effective way to reduce the time between rolling and planting is to spray herbicide while rolling. However, a continuous spray may not be required if a roller/crimper is used due to the additive effect of the roller. Two different methods of applying glyphosate (Roundup (TM)) to rolled rye were compared. First, a felt strip saturated with herbicide was attached to the roller's crimping bar to provide glyphosate application with every crimp. The second method consisted of a boom (five nozzles controlled by solenoid valves) mounted on the roller applying a spray continuously, and intermittent spray every second crimp, or every fourth crimp. The average results over three growing seasons showed that 7 days after rolling, rye termination rates for all rolled/glyphosate treatments surpassed 90% (91% for glyphosate saturated felt strip and 98% for continuous spray), exceeding the termination rates for rye recommended to planting cash crops into rye residue cover. For the roller/crimper alone and the non-treated check (standing rye), termination rates were 82% and 54%, respectively. Since spraying glyphosate every fourth crimp provided a 93% termination rate one week after rolling, this method may facilitate planting the cash crop in a timely fashion while reducing input costs. Economic savings of $12.63 to $36.87 ha(1) may be attained by incorporating herbicide applications with rolling activities. One and two weeks after the rolling treatment, volumetric soil moisture content for all rolled rye/chemical treatments were significantly higher than the non-treated check.