• Authors:
    • Neffati, M.
    • Belgacem, A. O.
    • Visser, M.
  • Source: Grass and Forage Science
  • Volume: 65
  • Issue: 1
  • Year: 2010
  • Summary: When grass species are used to reseed depleted drylands, grazing is often prescribed during the establishment phase. Total protection from grazing often leads to the presence of persistent weed species and is hard to accept by land users keen to graze reseeded land as soon as possible. The particular case of reseeding arid Mediterranean cereal fallows with one native grass species, Stipa lagascae (Stipa), in Tunisia was tested. Seedlings, derived from two different seed sources (selected and bulk), and volunteer annual weed species underwent four different cutting treatments to ground level (early cut, late cut, early and late cuts and no cuts). No effect of any of the treatments on seedling survival or dry matter mass of Stipa seedlings was found. It was concluded that Stipa seedlings are indifferent to the presence of annual weed species and can tolerate more than one cut during the year of establishment. In the context of the study, early grazing of reseeded fallows is worth investigating further.
  • Authors:
    • Thenua, O. V. S.
    • Sharma, U. C.
    • Abraham, T.
    • Shivakumar, B. G.
  • Source: The Indian Journal of Agricultural Sciences
  • Volume: 80
  • Issue: 5
  • Year: 2010
  • Summary: A field experiment was conducted during winter ( rabi) season of 2005-06 and 2006-07 in the Agronomy Research Farm of Amar Singh College, Lakhaoti, Uttar Pradesh to study the effect of levels of irrigation and fertility on chickpea ( Cicer arietinum L.) and mustard ( Brassica juncea L. czernj & coss.) in sole and intercropping systems. The experiment was conducted in split-plot design with 3 replications. The combination of treatments consisted of 3 cropping systems, namely sole mustard (C 1), sole chickpea (C 2) and chickpea+mustard intercropping (C 3) (4:1 raw ratio) and 4 irrigation levels [no irrigation (I 0), irrigation at pre-flowering (I 1), at pod formation (I 2) at both pre-flowering and pod formation (I 3)] for chickpea allotted to main plots and 3 fertility levels [F 1 (20:40:10 kg N, P 2O 5 and S/ha) F 2 (40:60:20 kg N, P 2O 5 and S/ha) and F 3 recommended dose of fertilisers (RDF)] for both the crops on row length basis to sub-plots. The sole Indian mustard recorded higher seed yield compared to intercropping. The yield reduction in mustard was to the tune of 58.9% and 60.0% in the first and second year, respectively, due to intercropping chickpea. Irrigation, on an average increased the mustard yield by 6.47% (I 1), 12.18% (I 2) and 13.18% (I 3) compared to no irrigation (I 0). Similarly fertilizer treatments F 2 and F 3 on an average increased mustard yield by 10.17% and 18.46%, respectively, over the F 1. The intercropping of chickpea and mustard in 4:1 raw ratio was significantly superior to sole crops of either chickpea or mustard in terms of yield and economics. Between the sole crops, chickpea was better as compared to mustard. Application of recommended dose of fertilizers (20:60:20 kg, N, P 2O 5 and S/ha) on area basis was superior.
  • Authors:
    • Frederick, J. R.
    • Fortnum, B. A.
    • Bauer, P. J.
  • Source: Agronomy Journal
  • Volume: 102
  • Issue: 4
  • Year: 2010
  • Summary: Longer rain-free periods are predicted to occur more often in the southeastern United States as a result of global climate change. This nonirrigated field study was conducted from 1997 through 2002, which coincided with the 1998-2002 drought that affected most of the United States. The objective was to determine the effect of rotation and tillage on cotton (Gossypium hirsutum L.) productivity. Treatments in the study were rotation [cotton rotated with corn (Zea mays L.), cotton planted after a rye (Secale cereale L.) winter cover crop, and continuous cotton with no cover crop] and tillage system (conventional tillage and conservation tillage). Two levels of aldicarb [2-methyl-2-(methylthio)propanal O-{(methylamino)carbonyl}oxime] (0 and 1.18 kg a.i. ha(-1)) were also included because of known soil management effects on thrips (Frankliniella sp.) and root-knot nematodes (Meloidigyne incognita). The predominant soil types were Bonneau loamy sand (loamy, siliceous, subactive, thermic Arenic Paleudult) and Norfolk loamy sand (fine-loamy, kaolinitic, thermic Typic Kandiudult). Rotation did not affect cotton yield in any year. Tillage did not affect cotton yield in 1997. Conservation tillage resulted in an average 25% yield increase in cotton lint yield over conventional tillage during the 5-yr drought. Tillage and aldicarb affected both thrips and root-knot nematodes, but lack of interaction among these factors for lint yield suggested that management of these pests was not the predominant cause for the cotton yield increase with conservation tillage. Conservation tillage for cotton production could be an important method to help mitigate the effects of climate change in the region if change occurs as predicted.
  • Authors:
    • Domuta, C.
    • Sandor, M.
    • Bara, L.
    • Bara, C.
    • Bara, V.
    • Domuta, C.
    • Borza, I. M.
    • Brejea, R.
    • Vuscan, A.
  • Source: Analele Universităţii din Oradea, Fascicula: Protecţia Mediului
  • Volume: 15
  • Year: 2010
  • Summary: The paper based on the researche carried out in the Agricultural Research and Development Station Oradea in the long term trial placed in 1990 on a preluvosoil. Two factors were studied: crop rotation (maize-monocrop; maize-wheat; maize-soybean-wheat) and water regime (unirrigated and irrigated). In comparison with unirrigated and irrigated monocrop, in the maize-wheat crop and especially in the maize-soybean-wheat crop rotation very significant yield gains were obtained all the three years. The irrigation determined the yield gains very significant statistically every year and in every crop rotation. The smallest protein content and protein production were registered in the variant with maize monocrop and the biggest in the variant with wheat-maize-soybean crop. The irrigation determined the increase of the protein content.
  • Authors:
    • Kochsiek, A. E.
    • Knops, J. M. H.
    • Walters, D. T.
    • Arkebauer, T. J.
  • Source: Agricultural and Forest Meteorology
  • Volume: 149
  • Issue: 11
  • Year: 2009
  • Summary: The litter carbon (C) pool of a single litter cohort in an agroecosystem is the difference between net primary productivity and decomposition and comprises 11-13% of the total C pool (litter and soil 0-15 cm depth) post-harvest. This litter-C pool is highly dynamic and up to 50% can be decomposed in the first 12 months of decomposition. Thus, understanding litter-C dynamics is key in understanding monthly and annual total ecosystem carbon dynamics. While the effects of management practices such as irrigation and fertilization on productivity are well understood, the effects on decomposition are less studied. While irrigation and fertilization increase productivity, this will only lead to increased litter-C residence time and litter-C pool accretion if these techniques do not also result in equivalent or greater increases in decomposition. Management could potentially have impacts on litter-C accretion by increasing litter inputs, changing plant-C allocation, plant tissue quality, or decomposition rates. We examined carbon loss of one annual cohort of maize litter using in situ nylon litter bags for 3 years in three no-till fields with differing management regimes: irrigated continuous maize with a pre-planting fertilization application and two fertigation events, irrigated maize-soybean rotation with the same fertilization regime as the irrigated continuous maize management regime, and rainfed maize-soybean rotation with a single pre-planting fertilization event. We addressed the effects of these different management regimes on net primary productivity and litter inputs, litter nitrogen (N) concentrations and carbon quality measures, plant C allocation, decomposition rates and the potential changes in the overall litter-C balance. We found that irrigation/fertigation management increased litter inputs, led to changes in plant tissue quality, had no effect on carbon allocation, and increased decomposition rates. This balance of both greater litter inputs and outputs of C from the irrigated management regimes led to a similar litter-C balance for this litter cohort in the irrigated and rainfed management regimes after 3 years of decomposition. Our data clearly show that merely increasing litter-C inputs through irrigation/fertigation practices is not sufficient to increase litter-C residence time because decomposition rates also increase. Therefore, close monitoring of decomposition rates is essential for understanding litter-C pool dynamics.
  • Authors:
    • Balasubramanian, A.
    • Lakshmi, K. V.
    • Sankaran, N.
  • Source: Madras Agricultural Journal
  • Volume: 96
  • Issue: 1-6
  • Year: 2009
  • Summary: A field experiment was conducted during North East Monsoon season of 2002 and 2003 at Tamil Nadu Agricultural University, Coimbatore to study the productive and economically viable integrated rainwater and nitrogen management practice for dryland maize under different rainfall situations. It is concluded that for early withdrawal of rainfall around 45 DAS, two supplemental irrigations given at tasseling and silking stages through run off recycling from farm pond increased growth, yield parameters, grain yield by 134 percent and net returns by Rs.3389 ha -1 over rainfed maize in 2002. For moisture stress at tasseling and soft dough stages, two supplemental irrigation increased growth, yield attributes, grain yield by 88 percent and net return by Rs. 3305 ha -1 over rainfed maize in 2003. Application of 40 kg N ha -1 with intercropping and incorporation of either sunnhemp or cowpea at 45 DAS increased yield and net returns of maize over sole maize with out inorganic nitrogen.
  • Authors:
    • Phillips, R. L.
    • Tanaka, D. L.
    • Archer, D. W.
    • Hanson, J. D.
  • Source: Journal of Environmental Quality
  • Volume: 38
  • Issue: 4
  • Year: 2009
  • Summary: Microbial production and consumption of greenhouse gases (GHG) is influenced by temperature and nutrients, especially during the first few weeks after agricultural fertilization. The effect of fertilization on GHG fluxes should occur during and shortly after application, yet data indicating how application timing affects both GHG fluxes and crop yields during a growing season are lacking. We designed a replicated ( n=5) field experiment to test for the short-term effect of fertilizer application timing on fluxes of methane (CH 4), carbon dioxide (CO 2), and nitrous oxide (N 2O) over a growing season in the northern Great Plains. Each 0.30-ha plot was planted to maize ( Zea mays L.) and treated similarly with the exception of fertilizer timing: five plots were fertilized with urea in early spring (1 April) and five plots were fertilized with urea in late spring (13 May). We hypothesized time-integrated fluxes over a growing season would be greater for the late-spring treatment, resulting in a greater net GHG flux, as compared to the early-spring treatment. Data collected on 59 dates and integrated over a 5-mo time course indicated CO 2 fluxes were greater ( P<0.0001) and CH 4 fluxes were lower ( P<0.05) for soils fertilized in late spring. Net GHG flux was also significantly affected by treatment, with 0.840.11 kg CO 2 equivalents m -2 for early spring and 1.040.13 kg CO 2 equivalents m -2 for late spring. Nitrous oxide fluxes, however, were similar for both treatments. Results indicate fertilizer application timing influences net GHG emissions in dryland cropping systems.
  • Authors:
    • Jyoti, K.
    • Tarunvir, S.
  • Source: Agricultural Situation in India
  • Volume: 66
  • Issue: 7
  • Year: 2009
  • Summary: This study examines the cost and returns of dry land maize in the Jammu District of Jammu and Kashir state in India; the resource use efficiency and estimates the extent of instability in cropped area, yield and net returns.
  • Authors:
    • Ranamukhaarachchi, S.
    • Thongsaga, K.
  • Source: Asia-Pacific Journal of Rural Development
  • Volume: 19
  • Issue: 1
  • Year: 2009
  • Summary: Water stress is unpredictable in rain-fed agriculture, and regularly affects maize production in Thailand. This study was conducted to determine the effect of 10-day dry period occurring during critical growth stages on growth and yield of maize, and to simulate and compare the performance using CERES-Maize model in DSSAT version 4.0.2.0 using concurrent weather data. Two popular maize hybrids, namely Suwan 4452 and Pacific 224, were subjected to four 10-day dry periods [viz. 36-45 days from seeding (DFS), 46-55 DFS, 56-65 DFS, and 66-75 DFS] as treatments together with a control grown with regular irrigation in a split plot design with four replicates. The experiment was conducted during the longest dry period, from December 2006 to April 2007, under controlled irrigation. Soil moisture content at 0-15 cm and 15-30 cm depths reached near the lower limit of readily available water (RAW) in six days, after the cessation of irrigation, which declined to near permanent wilting point (PWP), but did not reach PWP during the 10-day period. Leaf area index (LAI) (ranged from 4.3 to 4.6), plant height (ranged from 2.2 to 2.4 m) and biomass (ranged from 6.8 to 7.6 t/ha) at silking were not significantly affected by the 10-day suspension of irrigation, but various differences were observed in the plant height: Suwan 4452 was taller than Pacific 224. Number of grains per ear, 100-grain weight, grain yield and the harvest index remained unaffected due to the 10-day suspension of irrigation, but were significantly greater in Pacific 224 than Suwan 4452. CERES-Maize model showed excellent results in predicting time to silking, LAI and biomass at silking, 100-grain weight, grain yield and the harvest index. However, some deviations were found in Suwan variety for LAI and 100-grain weight, and of Pacific 224 in the time to silking. Comparisons showed that simulations were very much close, except for the cases noted. The model simulated responses similar to the actual values in this study.
  • Authors:
    • Wuest, S. B.
    • Siemens, M. C.
    • Gollany, H. T.
    • Williams, J. D.
    • Long, D. S.
  • Source: Journal of Soil and Water Conservation
  • Volume: 64
  • Issue: 1
  • Year: 2009
  • Summary: Conservation tillage systems that reduce Soil erosion and maintain or increase soil carbon offer long-term benefits for producers in the inland Pacific Northwestern United States but Could result in reduced grain yields due to increased pressure from weeds, disease, and insect pests. Our objective was to compare runoff, soil erosion, and crop yields from a conventional tillage, wheat-fallow two-year rotation and a no-till four-year rotation. The experiment was undertaken within a small,watershed to provide results that would be representative of conservation effectiveness at the field scale. Two neighboring drainages, 5.8 and 10.7 ha (14 and 26 ac), in the 340 mm y(-1) (13.4 in yr(-1)) precipitation zone of northeastern Oregon, were instrumented to record rainfall, runoff, and erosion over a four-year period (2001 through 2004). One drainage was cropped to a winter wheat-fallow rotation and received inversion tillage (tillage fallow). The second drainage was cropped in a four-year no-till rotation: winter wheat-chemical fallow-winter wheat-chickpea (no-till Fallow). We recorded 13 runoff events from the inversion tillage system and 3 from the no-till system. Total runoff and erosion values from inversion tillage drainage were 5.1 mm (0.20 in) and 0.42 Mg ha(-1) (0.19 tn ac(-1)) versus 0.7 mm (0.03 in) and 0.01 Mg ha(-1) (<0.005 in ac(-1)) from no-till drainage. The no-till rotation was substantially more effective in conserving soil and water in this field-scale comparison. Soil erosion observed in this research is a fraction of that reported for similar tillage practices outside of the Pacific Northwestern. Mean wheat yields did not significantly differ between inversion tillage and no-till treatment despite intensifying the rotation by replacing one year of fallow with a chickpea crop in the four-year rotation. Because of high year-to-year variability in yield and limited sample size, more study is needed to compare winter wheat yields in no-till production systems with inversion tillage. The no-till cropping system was more e effective in reducing runoff and soil erosion and provides producers with an ability to protect soil and water resources in the dryland Pacific Northwest.