591. Carbon and nitrogen mineralization and persistence of organic residues under conservation and conventional tillage.

• Authors:
  • Mulvaney, M. J.
  • Wood, C. W.
  • Kemble, J. M.
  • Balkcom, K. S.
  • Shannon, D. A.
• Source: Agronomy Journal
• Volume: 102
• Issue: 5
• Year: 2010
• Summary: A combination of high biomass cover crops with organic mulches may be an option for no-till vegetable production, but information on mineralization rates from these residues is lacking. The objective of this study was to assess nutrient release rates and persistence from mimosa ( Albizia julibrissin Durazz.), lespedeza [ Lespedeza cuneata (Dum. Cours.) G. Don], oat ( Avena sativa L.) straw, and soybean [ Glycine max (L.) Merr.] residues under conventional and conservation tillage. The experiment was conducted in Tallassee, AL using litterbag methodology in a split-plot design (main plots: two tillage systems; subplots: four residue types). Comparison of rate constants showed that labile portions of residues was more affected by tillage than recalcitrant portions. In spring, mimosa residue contained 78 kg N ha -1 when buried the previous fall, compared to 123 kg N ha -1 when surface placed; soybean residue showed similar results (39 vs. 72 kg N ha -1, respectively). Results were similar for lespedeza (72 vs. 101 kg N ha -1, respectively), but not for oat straw (24 vs. 26 kg N ha -1, respectively). After 1 yr, surface placed mimosa residue mineralized 33% of initial N compared to 71% when buried, while surface placed lespedeza mineralized 36% of initial N compared to 64% when buried. Soybean residue mineralized N quickly regardless of placement (73 vs. 87%, respectively). This study demonstrates that cut-and-carry mulches may be used under conservation tillage for the enhancement of soil organic matter (SOM), soil organic carbon (SOC), and soil N status.

592. Assessment of no-tillage and direct seeding technologies in rice-wheat rotation for saving of water and labour in western IGP.

• Authors:
  • Tomar, S. S.
  • Yadav, A. K.
  • Singh, A.
  • Pal, G.
  • Shahi, U. P.
  • Kumar, A.
  • Singh, B.
  • Gupta, R. K.
  • Naresh, R. K.
• Source: Progressive Agriculture
• Volume: 10
• Issue: 2
• Year: 2010
• Summary: Resource conserving technologies (RCTs) with double no-till practices represents a major shift in production techniques for attaining optimal productivity, profitability and water use in rice-wheat system in Indo-Gangetic plains. Conventional tillage and crop establishment methods such as puddled transplanting in the ricewheat ( Oryza sativa L.- Triticum aestivum L.) system in the Indo-Gangetic Plains (IGP) require a large amount of water and labor, both of which are increasingly becoming scarce and expensive. We attempted to evaluate alternatives that would require smaller amounts of these two inputs. A field experiment was conducted in the Western IGP for 2 years to evaluate various tillage and crop establishment systems for their efficiency in labor, water, and energy use and economic profitability. The soil physical properties (bulk density, mean weight diameter of aggregates and infiltration rate) improved significantly compared to puddled transplanted rice-conventional till wheat system. The wide beds and double no-till with flat layouts in rice-wheat system is under evaluation in different scenario of soil, climate, crop cultivars and seeding/crop establishment techniques (direct seeding, transplanting) and showed non consistent results. Systematic information on various aspects of narrow/wide beds is lacking. The productivity of rice with wide beds was at par compared to reduced tillage transplanted rice layouts but, the wheat productivity was reverse as it was highest under wide beds. The RW system productivity was highest with wide raised beds does differ significantly with other tillage and crop establishment techniques except with mulch crop establishment techniques. The water productivity of both rice and wheat was markedly improved with wide beds compared to other tillage and crop establishment techniques. Under research managed trials (rice on double no-till flat) with basmati rice, the profitability was maximum with ZTDSR (US $ 505 ha -1) and was least with direct seeded on narrow raised beds (US$305 ha -1). The study showed that the conventional practice of puddled transplanting could be replaced with no-tillage-based crop establishment methods to save water and labor. However, the occurrence and distribution of rainfall during the cropping season had considerable influence on the savings in irrigation water.

593. Technological Impact on Energy Requirements for Wheat Cultivation in North India

• Authors:
  • Singh, R.
• Source: AMA-Agricultural Mechanization in Asia, Africa and Latin Ameria
• Volume: 41
• Issue: 2
• Year: 2010
• Summary: India has emerged as the second largest producer of wheat in the world, close on the heels of China. Development and adoption of improved farm technologies has helped boost yields, provide resistance to important pests and diseases and other undesirable traits, spread of irrigation, storage, transport, processing and marketing, coupled with congenial price policies, all helping enhance the production and productivity of wheat. The transition in technology and agricultural development has brought in a shift in the choice of energy resources under use. The use of non-renewable energy sources has been increasing in the process. Adoption of an energy-efficient cultivation system would help in energy conservation and better resource allocation. For the wheat crop, data were collected from 780 irrigated farms spread over Tarai and Bhabar regions of Uttar Pradesh and five agro-climatic zones of the Punjab State. All the farms had the combination of tractor power and diesel engine and electric motor pumps as stationary power sources. The energy consumption patterns of these farms were studied and linear programming technique applied to determine optimal energy resource allocation for maximum yield obtainable under business-as-usual and improved cultivation practices. The results indicated that 16,635 MJ/ha of energy is presently consumed for an average yield of 3,646 kg/ha. Fertiliser provided 41 percent of the energy, followed by diesel, electricity, seed, farmyard manure, human, machinery and agro-chemicals. Based on the performance of the farms, optimal energy resource allocation suggests that 38.50 percent additional yield can be obtained without any major change in energy use pattern. Energy saving of 8.30 percent is also feasible with optimal energy resource allocations. Since the optimisation is based on actual performance of the sample size, it appears that the energy resource management by the majority of farmers has been sub-optimal. The results also suggest that by adopting improved cultivation practices and recommended seed and fertiliser application rates, the yield level can increase to 5,792 kg/ha with an investment of 17,230 MJ/ha of total energy. The optimized energy use requires 17.40 percent higher fertiliser, and 60.72 percent higher machinery energy for timely sowing of the crop with improved sowing implements and timely completion of time bound operations. Energy productivity in the process would increase to 0.336 kg/MJ from 0.219 kg/MJ presently being obtained by the farmers. The estimate of optimized energy resource allocation (using improved practices) required for attaining the potential yield level observed in research farms indicate that investment of 22,378 MJ/ha would be required for a yield level of 6,000 kg/ha. When compared with optimal energy resource allocation for business-as-usual approach, fertiliser use would increase by about 48 percent for the increase in yield by 19 percent. Diesel energy use would increase by 54 percent. As a consequence, electricity and human energy use would reduce by about 10 and 19 percent, respectively. The total energy consumption (using improved practices) increases with increase in productivity. The share of indirect energy increases faster than direct energy due to fertiliser consumption pattern. Energy productivity would improve to 0.426 kg/MJ, the rate of improvement being higher till yield level of 2,500 kg/ha. The total direct energy consumption in business-as-usual practice is, however, more than in the improved practice, the difference being more pronounced at lower productivity levels. The pattern is governed by the consumption pattern of direct commercial energy. The potential of saving of human energy and electricity in the process would provide a better energy management option for cultivation of the crop.

594. Assessing the impact of zero tilled wheat growing in rice ( Oryza sativa L.)-wheat ( Triticum aestivum L.) cropping systems: the case of central Uttar Pradesh in the Indo-Gangetic Plain.

• Authors:
  • Singh, V. K.
  • Sah, A. K.
  • Prakash, O.
  • Singh, R. K.
  • Singh, S. N.
• Source: Outlook on Agriculture
• Volume: 39
• Issue: 3
• Year: 2010
• Summary: Rice-wheat is the most commonly employed cropping system on around 14 million hectares of land extending across the Indo-Gangetic Plain (IGP). The IGP region covers the South Asian countries of Pakistan (2.2 million ha), India (10.5 million ha), Nepal (0.5 million ha) and Bangladesh (0.8 million ha). The major challenge facing the IGP's rice-wheat cropping system is to sustain long- term productivity. This system has a pivotal role in the food security and livelihoods of millions of farmers and workers of populous countries such as India, particularly in central Uttar Pradesh. The system's productivity and economic gains have been consistently decreasing, mainly because of the delayed sowing of wheat after the rice harvest and the fatigued soil condition. The region's farmers lose valuable time for pre-sowing irrigation and field preparation due to the gap of two to three weeks between the harvesting of rice and the planting of wheat. If wheat sowing is delayed beyond the optimal time (by late November), yields plummet at the rate of 30 kg per ha per day. The adoption of resource conservation technologies, such as zero tilled wheat sowing, is considered essential to maintain the productivity of the rice-wheat cropping system. Economic analysis of data for two years from six on- farm demonstrations shows that the zero tillage method of wheat cultivation is the most economical and attractive option for the farming community of central Uttar Pradesh. A high grain yield and reduced cost of cultivation per hectare, reduction in the density of weeds, especially Phalaris minor, and greater water saving were noted in zero tilled wheat sowings compared with conventional practices. As a result of field demonstrations and farmer training programmes, the introduction of zero till drill wheat sowing has expanded rapidly and has made significant contributions to the tillage revolution in the study area.

595. Analysis and modelling of the effects of water stress on maize growth and yield in dryland conditions.

• Authors:
  • Hanan, J.
  • Qu, S.
  • Doherty, A.
  • Song, Y.
  • Birch, C.
• Source: Plant Production Science
• Volume: 13
• Issue: 2
• Year: 2010
• Summary: It is essential to provide experimental evidence and reliable predictions of the effects of water stress on crop production in the drier, less predictable environments. A field experiment undertaken in southeast Queensland, Australia with three water regimes (fully irrigated, rainfed and irrigated until late canopy expansion followed by rainfed) was used to compare effects of water stress on crop production in two maize ( Zea mays L.) cultivars (Pioneer 34N43 and Pioneer 31H50). Water stress affected growth and yield more in Pioneer 34N43 than in Pioneer 31H50. A crop model APSIM-Maize, after having been calibrated for the two cultivars, was used to simulate maize growth and development under water stress. The predictions on leaf area index (LAI) dynamics, biomass growth and grain yield under rainfed and irrigated followed by rainfed treatments was reasonable, indicating that stress indices used by APSIM-Maize produced appropriate adjustments to crop growth and development in response to water stress. This study shows that Pioneer 31H50 is less sensitive to water stress and thus a preferred cultivar in dryland conditions, and that it is feasible to provide sound predictions and risk assessment for crop production in drier, more variable conditions using the APSIM-Maize model.

596. Corn Yield Response to Nitrogen Fertilizer and Irrigation in the Southeastern Coastal Plain

• Authors:
  • Millen, J.
  • Evans, D.
  • Sadler, E.
  • Camp, C.
  • Stone, K.
• Source: Applied Engineering in Agriculture
• Volume: 26
• Issue: 3
• Year: 2010
• Summary: Availability of spatially-indexed data and crop yield maps has caused increased interest in site-specific management of crop inputs, especially water and fertilizer As commercial equipment to implement site-specific applications of water and nutrients becomes available, crop response to variable inputs and decision support systems will be required to ensure profitable crop production while conserving natural resources and protecting the environment. The objective of this research was to determine corn yield response to a range of nitrogen fertilizer and irrigation amounts on a relatively uniform southeastern Coastal Plain soil under conservation tillage. Corn was grown in a field experiment using a center pivot irrigation system that had been modified to make site-specific applications of water and fertilizer during the period 1999-2001 on a site near Florence, South Carolina. Treatments included three antecedent crop rotations (prior four years), three irrigation regimes (0, 75%, and 150% of a base rate, IBR), and four nitrogen fertilizer amounts (50%, 75%, 100%, and 125% of a base rate, NBR), and with Put. replications. As expected, corn grain yields increased with irrigation and N fertilizer Mean corn grain yields for the three-year study ranged from 6.3 to 8.9 Mg/ha for the 0% IBR avail-twin, 9.4 to 10.5 Mg/ha for the 75% IBR treatment, and 10.0 to 10.6 Mg/ha for the 150% IBR treatment. The mean corn grain yields in response to N applications ranged from 6.4 to 8.0 Mg/ha for the 50% IBR treatment, 8.6 to 9.4 Mg/ha for the 75% NBR treatment, 9.1 to 10.9 Mg/ha for the 100% NBR treatment, and 8.8 to 11.7 for the 125% NBR treatment. However, the nature of the response varied among the three years, mainly because of differences in rainfall and rainfall distribution during the growing season. Also, during the first,year there was less response to N fertilizer (7.9 to 9.1 Mg/ha) possibly because of residual soil N from antecedent soybean crop. A regression analysis indicated that the slopes of the corn yield response to increased N fertilizer application were low for both irrigated and rainfed treatments in 1999. In both 2000 and 2001, the slopes were greater for the corn yield response to increased N fertilizer In 2000, the irrigated treatments had a greater slope of the yield response for additional N fertilizer than did the minted treatments. Using an orthogonal contrast analysis, the overall yield response for the combined irrigation treatments to N fertilizer was quadratic in 1999 and 2000, and linear in 2001. These quadratic yield response's indicated that, for these conditions, a potential upper limit on production for the applied N-fertilizer and water (rainfall and irrigation) was approached. For the minted treatment, yield response to N fertilizer was linear in all three years. These results provide useful information that should be helpful in developing management strategies and decision support systems for profitable management of both water and N fertilizer on spatially-variable soils in the southeastern Coastal Plain while conserving natural resources and protecting the environment.

597. Effects of organic amendment and tillage on soil microorganisms and microfauna.

• Authors:
  • Maul, J. E.
  • Buyer, J. S.
  • Austin, E. E.
  • Treonis, A. M.
  • Spicer, L.
  • Zasada, I. A.
• Source: Applied Soil Ecology
• Volume: 46
• Issue: 1
• Year: 2010
• Summary: Soil microorganisms (bacteria, fungi) and microfauna (nematodes, protozoa) have been shown to be sensitive to organic amendments, but few experiments have investigated the responses of all these organisms simultaneously and across the soil profile. We investigated the impact of organic amendment and tillage on the soil food web at two depths in a field experiment. Over three growing seasons, field plots received seasonal organic amendment that was either incorporated into the soil (tilled) or not (no-till) as part of a tomato/soybean/corn cropping system. Un-amended, control plots that were either tilled or no-till were also included. We hypothesized that the addition of amendments would have a bottom-up effect on the soil food web, positively influencing the abundance of microorganisms, protozoa, and nematodes, primarily in the surface layers of the soil, but that this effect could be extended into deeper layers via tillage. Organic amendment had positive effects on most measured variables, including organic matter, respiration, protozoan and nematode density, and the abundance of PLFA biomarkers for bacteria and fungi. These effects were more pronounced in the 0-5 cm depth, but most variables increased with amendment in the deeper layer as well, especially with tillage. Denaturing Gradient Gel Electrophoresis (DGGE) of bacterial rDNA fragments indicated that distinct bacterial communities were selected for among tillage and amendment treatments and depths. Nematode faunal indices were not influenced by amendment, however. Increased nematode density in amended soils encompassed all trophic groups of free-living nematodes, with the greatest response among fungal-feeders, particularly with tillage. Increased biomass of microorganisms and decomposer microfauna in amended, tilled soils (0-5 cm depth) corresponded with a decline in the abundance of plant-parasitic nematodes. In control soils (0-5 cm depth), tillage reduced the relative abundance of fungal-feeding nematodes and increased the density of bacterial-feeding nematodes, in particular nematode species contributing to the Enrichment Index. When combined with organic amendment however, tillage was associated with increases in fungal-feeding nematodes and fungal biomarker PLFA. The results of this study suggest that when combined with amendment, tillage enhances the soil food web beyond the effect of amendment alone and is associated with declines in plant-parasitic nematodes.

598. Research on crop stage water consumption with two crops a year on dry-land in hilly areas.

• Authors:
  • Zhang, X.
  • Shi, F.
  • Li, B.
  • Xue, Y.
  • Yang, Z.
• Source: Journal of Henan Agricultural Sciences
• Issue: 10
• Year: 2010
• Summary: By using field monitoring methods, the village, the water consumption of winter wheat grown Zhangcun town of Huixian county, Henan province were determined. Water consumption can reach 216.3-345.2 mm at the yield level of 4 500-6 000 kg/ha. The water consumption percentage constitution of different growing period was 25.9%-36.9% between seeding and reviving stages, 22.0%-31.1% between reviving and heading stages, and 31.9%-52.2% between heading and maturation. The variation was great among different years. When the yield level of corn was 6 750-7 500 kg/ha, water consumption 299.6-462 mm which account for 81.3%-97.4% of precipitation during the period of the year. The water consumption percentage constitution of different growing period was 17.1%-17.3% between seeding and jointing stages, 34.5%-39.1% between jointing and trumpet stages, and 43.6%-48.4% between trumpet and maturation stages. For both wheat and corn, the water consumption density increased dramatically after jointing stage. The jointing and seed filling stages were two important periods for wheat water consumption. The trumpet stage was important for corn. In the dry-land hilly areas of middle and north Henan province at the current situation, natural precipitation can generally meet the water demand of autumn grain crops, while for summer grain crops, it is inadequate. So the emphases of water-saving irrigation should be on the summer grain crops.

599. Impact of cropping patterns and fertilizer treatments on the organic fertility of slightly eroded Pirsabak soil series in NWFP, Pakistan.

• Authors:
  • Naeem, M.
  • Khan, F.
  • Ahmad, W.
• Source: Soil and Environment
• Volume: 29
• Issue: 1
• Year: 2010
• Summary: This study was undertaken as a part of soil fertility management of eroded soils in NWFP, Pakistan. The study was started in summer 2006 and continued for four consecutive crop seasons till winter 2007, in District Swabi, NWFP, Pakistan. Soil fertility status of the experimental site was determined before the start of the experiment. The experiment was laid out in a factorial split plot design using two factors viz cropping patterns and fertilizer treatments. The cropping patterns included maize-wheat-maize rotation, maize-lentil-maize rotation and maize-wheat+lentil intercrop-maize rotation and these were kept in main plots whereas the fertilizer treatments included control, 50% NP, 100% NPK and 20 t ha -1 farmyard manure integrated with 50% N and 100% PK as mineral fertilizers which were placed in sub plots. Fertilizers were applied for four seasons continuously. At the end of winter 2007, soil samples from two depths (0-20 cm and 20-40 cm) were collected from each plot and analyzed for microbial biomass carbon (MBC) at day 3, day 6 and day 10 incubation periods, total nitrogen (TN), microbial biomass nitrogen (MBN), and mineralizable nitrogen (MN). Results showed significant improvement in organic fertility of soil with fertilizer addition and cropping patterns. Combined application of organic and inorganic fertilizers (20 t ha -1 farmyard manure integrated with 50% N and 100% PK) showed 55, 25, 18 and 61% increase in total N, MBN, MN, and MBC after 10 days incubation period over the control, respectively, in the surface soil whilst 100% NPK showed 44, 15, 6 and 45% improvement over the control treatment for the same parameters in surface soil. Data further showed 43, 23, 19 and 60% increase in the corresponding microbial parameters in combined organic and inorganic fertilizer treatment over the control treatment in sub soil whilst 100% NPK showed 39, 20, 10 and 54% increase in TN, MBN, MN and MBC over the control in sub soil. The cropping patterns having cereal-legume rotation also improved organic soil fertility and showed 27 and 13% more total N and MBC after 10 days incubation period over the cereal-cereal rotation respectively and the improvement in MBN and MN in cereal-legume rotation over cereal-cereal rotation was non significant in surface soil. In the sub-surface soil cereal-legume rotation improved TN, MBN, MN and MBC by 9, 6, 8 and 28% over the cereal-cereal rotation. It was concluded that there is sufficient potential to improve soil organic fertility in Pirsabak soil series, the restoration of which on sustained basis would require at least 50% N from the organic sources. Moreover legumes must be included in the traditional cereal-cereal cropping pattern to further improve the N input and organic fertility of these soils.

600. Single- and twin-row peanut production within narrow and wide strip tillage systems.

• Authors:
  • Boykin, D.
  • Balkcom, K.
  • Arriaga, F.
  • Balkcom, K.
• Source: Agronomy Journal
• Volume: 102
• Issue: 2
• Year: 2010
• Summary: Increased production costs and potential benefits of maintaining surface residue has renewed interest in conservation tillage systems for peanut ( Arachis hypogaea L.) production. We determined surface residue cover from rye ( Secale cereale L.) or oat ( Avena sativa L.) cover crops after two strip tillage systems (narrow vs. wide) and planting operations with different row configurations (single vs. twin). We also compared plant populations, yields, and total sound mature kernels for three peanut cultivars ('ANorden', 'AP-3', and 'Georgia-02C') across each treatment combination. Seven site-years were examined across similar soil types in Alabama and northern Florida during the 2004 to 2006 growing seasons. The highest surface residue counts were for the narrow tillage system planted in single rows. Final plant stands were influenced by an interaction between cultivar and row configuration, with 'ANorden' planted in single rows below recommended rates. Peanut yields were affected by strip tillage system and row configuration, but differences among cultivars were also observed. Twin-row peanut yields were 5% greater than single-row peanut yields in the narrow strip tillage system but were similar across strip tillage systems. Cultivars 'AP-3' and 'Georgia-02C' yielded 20% higher than 'ANorden'. Total sound mature kernels were only affected by peanut cultivar, with the cultivar 'Georgia-02C' producing the highest-quality peanut, followed by 'ANorden' and 'AP-3'. These results indicate that growers interested in using twin rows for peanut production can also take advantage of a narrow strip tillage system that maximizes surface residue coverage and subsequent benefits.