• Authors:
    • Brainard, D.
  • Source: Acta Horticulturae
  • Issue: 950
  • Year: 2012
  • Summary: In response to declines in yield and stand longevity, Michigan asparagus growers are experimenting with multiple cultural practices including irrigation, shallow tillage, and "living-mulches" sown immediately following harvest in late June. Drought stress may play an important role in limiting fern growth and increasing fern susceptibility to pests. Living mulches are thought to reduce soil degradation and suppress weeds, but may also suppress asparagus through competition for water. Research was initiated in Hart, Michigan, USA, in 2008 with the following long-term objectives: (1) to evaluate the effects of irrigation on asparagus yields and weed management under two cropping systems; and (2) to determine the effects of cereal rye ( Secale cereal) living-mulch on soil moisture, weed growth, and asparagus yield. In a research farm field experiment, 4 treatments were examined: (1) no-till with standard herbicides; (2) no-till with standard herbicides plus irrigation; (3) shallow-tillage with rye living-mulch; (4) shallow tillage with rye living-mulch plus irrigation. Irrigation increased weed density and weed dry weight but had no detectable effect on asparagus yields. Rye living mulch (1) reduced soil volumetric water content by approximately 2-3% at 60 cm; (2) suppressed weeds compared to weedy control treatments, but resulted in increased weed density and dry weight compared to conventional herbicide treatments; and (3) had no detectable effect on asparagus yield.
  • Authors:
    • Noyes, D. C.
    • Bakker, J.
    • Brainard, D. C.
    • Myers, N.
  • Source: HortScience
  • Volume: 47
  • Issue: 1
  • Year: 2012
  • Summary: Living mulches growing below asparagus ( Asparagus officinales) fern can improve soil health and suppress weeds but may also suppress asparagus through competition for water or nutrients. The central objective of this research was to test whether cereal rye ( Secale cereale) living mulch, in combination with overhead irrigation, could provide comparable weed suppression to standard residual herbicides without reducing asparagus yields. A field experiment was conducted from 2008 to 2010 in a mature asparagus planting on sandy soils in western Michigan to evaluate the effects of irrigation (none vs. overhead) and weed management systems (standard herbicides vs. rye living mulch) on weed suppression, soil moisture content, and asparagus yield. Rye living mulch and herbicide treatments were established immediately after asparagus harvest in late June of each year. Rye living mulch reduced soil-available water in early August by 26% to 52% compared with herbicide treatments but had no detectable effect on asparagus yields. Compared with herbicide treatments, rye living mulch reduced fall-germinating weed emergence and resulted in lower densities of horseweed ( Conyza canadensis) during asparagus harvest. However, in 2 of 3 years, the living mulch system resulted in higher densities of summer annual weeds - including Powell amaranth ( Amaranthus powellii) and longspine sandbur ( Cenchrus longispinus) - during the fern growth period compared with herbicide treatments. After 3 years, the density of summer annual weeds was more than 10-fold greater in rye living mulch treatments compared with standard residual herbicides treatments. Our results suggest that (1) soil-improving rye cover crops can partially suppress weeds but may also compete with asparagus for soil moisture in dry years unless irrigation is used; and (2) successful use of rye living mulches for weed management will depend on identification of complementary weed management practices to avoid build-up of the summer annual weed seedbank.
  • Authors:
    • Sood, A.
    • Jalota, S. K.
    • Buttar, G. S.
    • Bhushan, B.
  • Source: INDIAN JOURNAL OF AGRICULTURAL SCIENCES
  • Volume: 82
  • Issue: 1
  • Year: 2012
  • Summary: Cotton cultivation in semi-arid region of Indian Punjab is considered as most risky crop as its yield is very sensitive to weather parameters like rain and temperature. In future due to global warming increase in the temperature is expected, which is most likely to influence the growth and yield of this fiber crop like other cereal crops. Studies on the effect of temperature on the growth and seed yield of Bt cotton in this region are lacking. The present 2-year field and 15-year simulation studies concern to simulate the effect of temperature on duration of pheno-phases and seed yield of Bt cotton hybrid RCH 134 and also on crop water productivity. Simulations were run for 15 years (1991-2005) using the already customized CropSyst model. The simulated results indicated that with increase in temperature from 28 to 32degreesC, cotton seed yield was reduced to half (from 4 700 to 2 300 kg/ha) following a linear relation with high coefficient of determination (0.97), and the reduction was more with increased temperature during sowing to flowering stage than other pheno-phases. Total evapo-transpiration (ET) during crop period and crop water productivity was also decreased with increased temperature. Relationship of cotton seed yield was linear with ET and quadratic with total water supply (rain+irrigation). Real crop water productivity (yield/ET) and apparent crop water productivity (yield/irrigation water) were 0.3620.129 and 0.4850.120 kg/m 3, respectively.
  • Authors:
    • Darshana
    • Pandey, A.
    • Pandey, R. P.
    • Ostrowski, M.
  • Source: Irrigation and Drainage
  • Volume: 61
  • Issue: 2
  • Year: 2012
  • Summary: In this study, simulation and optimization models were assembled for the optimization of irrigation systems and their operation. The simulation model CROPWAT was used for estimation of the crop water requirement, time and depth. The evolutionary algorithm (GANetXL) was used for the optimal planning of cropping pattern, maximization of net benefits and minimization of irrigation water requirements for the study area of Holeta catchment, Ethiopia. The study area encompasses three command areas, i.e. farm A, farm B and Tsedey State Farm, and five different type of crops, i.e. potato, tomato, apple, peach and winter wheat. The simulation results of the CROPWAT model illustrated that crop water requirement for apple was highest (993 mm), followed by peach (908 mm), tomato (470 mm), potato (443 mm) and wheat (294 mm). The study reveals that fruit crops have more crop water requirements than cereals. The results of the GANetXL show that when the cropped area and water allocated was varied between extreme values, 23% of water can be saved. The total benefit from the study area can be enhanced by USD 34 ha -1 and can be helpful in improving the economic conditions of the farmers.
  • Authors:
    • Ganesh-Kumar, A.
    • Pullabhotla, H.
    • Gupta, N.
    • Shreedhar, G.
    • Gulati, A.
  • Issue: 1159
  • Year: 2012
  • Summary: This paper reviews the key policies with regard to agriculture inputs such as seed, fertilizer, water, agricultural equipment, research, extension, and agricultural credit. It also provides an overview of the policies and programs related to agricultural output markets that are crucial for improving cereal production in the country. A review of the past performance and policies of India's foodgrain sector reveals that the main drivers of growth have been modern inputs and technology, institutions, and markets with the changing role of the public and private sectors. The present challenge facing Indian policymakers is to efficiently balance food security concerns and higher growth objectives. This will require not only pushing the production frontier to sustainably augment supply, but also ensuring strategic management of foodgrains including procurement and distribution. The review of input policies highlights the pressure placed on foodgrain systems, in a business-as-usual scenario that extensively subsidizes input and promotes their intensive usage. Fallouts such as excessive groundwater withdrawals and distorted application of nitrogenous fertilizers have implications on the environmental sustainability of natural resources apart from being a considerable fiscal burden. The current policy of subsidizing agricultural power, irrigation, and fertilizers has outlived its relevance and is actually constraining agricultural investments in areas where the returns are higher. Although it is difficult to completely remove these subsidies, they still need to be gradually phased out and converted into investments in rural infrastructure (especially roads) and research and extension systems, which desperately need to be (re)vitalized. It is time the government started to actively partner with the private sector (in infrastructure creation and research) and civil society organizations (in extension), as they have played an increasingly important role in recent years. The review of the output management policies show that the current policy paradigm consisting of public procurement of grains at a preannounced minimum support price, public storage, and public distribution has resulted in distortions across crops, especially rice and wheat, as well periodic buildup of large stockpiles and stock rundown of these grains at a high cost to the government. Moreover, public procurement and stocking, coupled with interventionist international trade policies, is often at variance with the trends in international markets, resulting in lost opportunities for Indian exporters of rice and wheat. The regional concentration of the system of public procurement in the northern states, aided by intra-country trade and movement restrictions, has also resulted in large spatial disparity in agricultural productivity and farm income as well as uneven development of output markets across states. As a result, producer and consumer welfare is often compromised, even though the government's objective is to maintain a balance between them. Major reforms on the output side would include linking of MSPs with market prices, allowing futures markets in cereals, liberalizing international trade and bring forth greater competition in domestic trade to ensure output markets are more uniformly developed across states and that the country has a truly integrated market for foodgrains.
  • Authors:
    • Maibody, S. A. M. M.
    • Arzani, A.
    • Golabadi, M.
  • Source: Cereal Research Communications
  • Volume: 40
  • Issue: 2
  • Year: 2012
  • Summary: Grain protein content (GPC) in durum wheat is a crucial determinant of pasta quality and as such is an important economic factor. This study was carried out to determine the microsatellite markers (SSRs) as associated with GPC in durum wheat grown under normal and moisture stress conditions. F 3 and F 4 population derived from 151 F 2 individuals developed from a cross between Oste-Gata (drought tolerant) and Massara-1 (drought susceptible) genotypes, were used. The population was evaluated under four environmental conditions (two irrigation regimes in two growing seasons). The results of single marker regression analysis (SMA) revealed that 2, 4 and 10 markers to be associated with GPC, test weight (TW) and 1000 grain weight (TGW), respectively. These markers explained between 4.4 and 21.8% of the phenotypic variation in either environmental condition. The most significant marker observed for GPC was located on 5B chromosome near Xgwm408 under normal conditions and the other marker was observed on 1A, explaining about 15% of phenotypic variance. However, it was not recognized any marker related to GPC under drought stress conditions. Xgwm408 marker was coincident with the markers identified for TW, TGW and components of grain yield under drought stress conditions. In spite of 5B, the other chromosomes such as 2B and 3B were related to quantitative traits like TW and TGW. Composite interval mapping (CIM) identified 4 and 5 putative minor and major QTL for TW and TGW, respectively. Two QTL near Xbarc101 and Xbarc124 markers on 3B and 2B chromosome, explained up to 45.2 and 6% of phenotypic variations of TGW and TW, respectively.
  • Authors:
    • Oweis, T.
    • Karrou, M.
  • Source: Agricultural Water Management
  • Volume: 107
  • Year: 2012
  • Summary: Selecting appropriate crops and applying deficit irrigation can help increase water productivity in water-limited regions such as the Mediterranean. The objective of this study was to develop water production functions of major cereal and legume crops under the same environmental and management conditions. Bread and durum wheat, faba bean, chickpea, and lentil were grown under full supplemental irrigation (FSI), two deficit irrigations levels of 2/3 of FSI (2/3SI) and 1/3 of FSI (1/3SI), and under rainfed conditions (no irrigation). In average, the actual evapotranspirations (ETs) under FSI were 549, 552, 365, 451 and 297 mm, for bread wheat, durum wheat, faba bean, chickpea and lentil, respectively. For the same crops, they were 463, 458, 330, 393 and 277 mm for the treatment 2/3SI and 357, 351, 265, 318 and 244 mm for the treatment 1/3SI, respectively. In the case of the rainfed treatment, ETs for the mentioned crops were 250, 251, 227, 237 and 215 mm, respectively. The experiment was conducted at the ICARDA experimental station at Tel Hadya, near Aleppo, Syria, over three growing seasons from 2007 to 2010. Results showed that, in general, the treatment with 1/3 of FSI gave the highest rate of increase in grain yield and water productivity. The mean grain yield from rainfed, 1/3SI, 2/3SI, and FSI were 1.36, 3.82, 5.18, and 5.70 t/ha for bread wheat; 1.24, 3.80, 5.10, and 5.75 t/ha for durum wheat; 1.57, 2.35, 2.86, and 3.54 t/ha for faba bean, 1.36, 2.63, 3.36, and 3.74 t/ha for chickpea, and 0.64, 1.16, 1.42, and 1.58 t/ha for lentil respectively. Grain yield reductions due to the application of 2/3SI were around 10, 5, 15.6, and 10.2% of FSI on average for wheat, chickpea, faba bean, and lentils, respectively. Deficit irrigation at 2/3SI increased water productivity compared to rainfed treatments, by 200, 223, 126, 148 and 190% for bread wheat, durum wheat, faba bean, chickpea, and lentils, respectively. However, differences in total water productivity of crops grown under full irrigation compared to deficit irrigation were not significant. Irrigation water productivity ranged from 25 kg ha -1 mm -1 in wheat with 1/3SI to 10 kg ha -1 mm -1 for legumes under the FSI treatment. Unlike legumes, maximizing wheat grain yield caused a decline in water productivity.
  • Authors:
    • Kutu, F. R.
  • Source: African Journal of Agricultural Research
  • Volume: 7
  • Issue: 26
  • Year: 2012
  • Summary: Conservation agriculture experiment was conducted under irrigated and dryland conditions during 2007/2008-summer cropping season to determine a suitable soil-crop management practice for increase maize yield. The study consisted of tillage practices (conventional, minimum and zero), cropping systems (sole and intercrop plots) and fertilizer regimes (unfertilized control, low, adjusted low and optimum) as treatments. Minimum and zero tillage practices constituted the conservation agriculture tillage practices while supplementation of low fertilizer rate with seed inoculation using growth enhancing microbial inoculant constituted the adjusted low fertilizer rate. Fertilizer application gave a significant (P
  • Authors:
    • Thomashow, L. S.
    • Parejko, J. A.
    • Mavrodi, D. V.
    • Mavrodi, O. V.
    • Weller, D. M.
  • Source: Applied and Environmental Microbiology
  • Volume: 78
  • Issue: 9
  • Year: 2012
  • Summary: This work determined the impact of irrigation on the seasonal dynamics of populations of Pseudomonas spp. producing the antibiotics phenazine-1-carboxylic acid (Phz +) and 2,4-diacetylphloroglucinol (Phl +) in the rhizosphere of wheat grown in the low-precipitation zone (150 to 300 mm annually) of the Columbia Plateau of the Inland Pacific Northwest. Population sizes and plant colonization frequencies of Phz + and Phl +Pseudomonas spp. were determined in winter and spring wheat collected during the growing seasons from 2008 to 2009 from selected commercial dryland and irrigated fields in central Washington State. Only Phz + bacteria were detected on dryland winter wheat, with populations ranging from 4.8 to 6.3 log CFU g -1 of root and rhizosphere colonization frequencies of 67 to 100%. The ranges of population densities of Phl + and Phz +Pseudomonas spp. recovered from wheat grown under irrigation were similar, but 58 to 100% of root systems were colonized by Phl + bacteria whereas only 8 to 50% of plants harbored Phz + bacteria. In addition, Phz +Pseudomonas spp. were abundant in the rhizosphere of native plant species growing in nonirrigated areas adjacent to the sampled dryland wheat fields. This is the first report that documents the impact of irrigation on indigenous populations of two closely related groups of antibiotic-producing pseudomonads that coinhabit the rhizosphere of an economically important cereal crop. These results demonstrate how crop management practices can influence indigenous populations of antibiotic-producing pseudomonads with the capacity to suppress soilborne diseases of wheat.
  • Authors:
    • Asebedo, R.
    • Ruiz-Diaz, D.
    • Mengel, D.
    • Maxwell, T.
  • Source: Better Crops with Plant Food
  • Volume: 96
  • Issue: 1
  • Year: 2012
  • Summary: Soybeans are not generally considered responsive to N fertilizer; however, there are some circumstances where this crop can benefit from addition of N. Kansas research performed several years ago and reported in this magazine showed the potential for soybean grain response to N fertilizer in high-yield irrigated conditions. This article looks at other conditions where N fertilizer can be beneficial in soybean production.