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Showing papers in "Field Crops Research in 2000"


Journal ArticleDOI
TL;DR: Biological nitrogen (N 2 ) fixation is key to sustainable agricultural systems in tropical soils, which are frequently deficient in N, but high temperature, drought and soil acidity constrain legume root-nodule formation and function in the tropics.

610 citations


Journal ArticleDOI
TL;DR: It is concluded that pod length is a suitable trait for indirect selection in plant breeding because it is correlated with pod length, which determines seed yield.

600 citations


Journal ArticleDOI
TL;DR: The different factors that affect dormancy in weed seed banks in soil are discussed, aiming to set a conceptual basis that will facilitate the construction of predictive models and stress the importance of clarifying the interaction between soil thermal and hydric conditions in the modification of the degree of dormancy of seed populations.

520 citations


Journal ArticleDOI
TL;DR: In this paper, the authors use simple empirical models to predict seedling emergence and use these models to better describe the direct and interactive effects on seed dormancy alleviation and induction, seed germination, and seedling elongation.

511 citations


Journal ArticleDOI
TL;DR: Only an integrated and multidisciplinary approach can determine if (a) N2-fixing symbioses with Gramineae really exist, and (b) if they are effective in agronomic terms.

417 citations


Journal ArticleDOI
TL;DR: This review contrasts the potential contribution of biologically fixed N to intensive and extensive agricultural systems, and examines opportunities for continued major contributions in the latter.

392 citations


Journal ArticleDOI
TL;DR: In this paper, a survey of long-term trends in N2 fixation by selected grain legumes is included, and some possible explanations for the observed stagnation in efforts to increase N 2 fixation under field conditions are presented.

390 citations


Journal ArticleDOI
TL;DR: To improve confidence in isotopic techniques for estimating N2 fixation differences in the form and function of plant roots are highlighted as critical areas for future research, as is a greater understanding of the total N contained in legume roots.

373 citations


Journal ArticleDOI
TL;DR: The potential for nitrogen savings by the use of site-specific N fertilization rates is reviewed and the late stalk nitrate test and the post-harvest soil mineral N test appear to be the most valuable.

317 citations


Journal ArticleDOI
TL;DR: In this article, a field experiment on maize crops for two years (1996-1997) in a semi-arid region of northwest China was conducted, where a controlled soil water deficit, either mild (50% of field capacity) or severe (40-50%), was applied at both the seedling and the stem-elongation stages.

308 citations


Journal ArticleDOI
TL;DR: It is only through an understanding of the needs and limitations of both the products physical and Rhizobium/Bradyrhiz Obium requirements that an effective and efficient legume inoculant can be commercially produced.

Journal ArticleDOI
TL;DR: Some of the recent advances in the field of environmental photomorphogenesis are discussed and their agricultural implications are highlighted.


Journal ArticleDOI
TL;DR: Benefit : cost ratio of fertilizer inputs and green manuring practices increased in both crops and for all treatments, indicating that the benefit accruing from fertilizer improved with time.

Journal ArticleDOI
TL;DR: Analysis of yield trends and effect of fertiliser NPK application, alone or in combination with farmyard manure, green manure or wheat crop residue incorporation, on the changes in soil organic carbon (OC) and available NPK contents indicates the advantage of combined use of manures plus fertilisers over fertilisers alone in sustaining crop yields.

Journal ArticleDOI
TL;DR: In this paper, a new mechanistic model of N uptake and redistribution in wheat crops incorporating the effects of N shortages through variation in leaf area is described, based on the assumption that the concentration of N in green tissue can be approximated as constant per unit leaf area and that excess N is stored in non-green tissue.

Journal ArticleDOI
TL;DR: Examining the factors influencing legume usage in Mediterranean agriculture and the changing focus on legumes in southern Australia is used to illustrate new roles for legume in evolving farming systems shows that root-nodule bacteria are important in maximising productivity in these systems.

Journal ArticleDOI
TL;DR: Agarwal et al. as discussed by the authors reviewed methodologies for breeding striga-resistant sorghums, including the use of agar-gel assay to screen host genotypes in the laboratory for low production of the striga seed germination stimulant.

Journal ArticleDOI
TL;DR: It is suggested that new genotypes are needed to achieve lodging-proof wheat crops, particularly to provide stronger basal internodes and a wider root plate per shoot.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the response of maize kernel number to plant density in four hybrids released in Argentina between 1965 and 1993, and concluded that more kernels per unit PGRs, rather than greater PGR, accounted for the genetic improvement of yield potential in the hybrids investigated.

Journal ArticleDOI
TL;DR: In this article, the authors measured the net photosynthetic rate (An), stomatal conductance (gs), chlorophyll content and dark respiration rate on 16 wheat cultivars (Triticum aestivum L.), grown in replicated yield trials in a warm, irrigated, and low relative humidity environment in central Mexico.

Journal ArticleDOI
TL;DR: Results from research programs to define genetic variation in N 2 fixation of soybean and to enhance N 2fixing through breeding are presented, with emphasis on symbiotic tolerance to nitrate, mutagenesis-induced supernodulation and promiscuous and selective nodulation.

Journal ArticleDOI
TL;DR: Three criteria that should be met in a crop modeling paper to make it suitable for scientific publication are suggested: a clear statement of a scientific objective with a defined domain of relevance, a mechanistic framework, and an evaluation of the scientific innovation offered in the new model.

Journal ArticleDOI
TL;DR: In this article, four treatments, i.e., control (ECe=1.6dSm−1), 70, 140, and 210m−m−3 NaCl were applied when the plants were three weeks old and the experiment continued until maturity.

Journal ArticleDOI
TL;DR: Nitrogen-fixing root nodules are found in 10 plant families containing trees and shrubs associated with rhizobia or Frankia, and future research to detail nodulation status, nitrogen fixation rates, physiological adaptations and genetic diversity in both legumes and actinorhizal trees will provide fundamental knowledge to further conservation and utilisation of these plants.

Journal ArticleDOI
TL;DR: It is desirable that the quality of legume inoculant be protected by some form of governmental regulation because many manufacturers are unable or unwilling to institute or enforce rigorous internal quality control procedures.

Book ChapterDOI
TL;DR: Soyabean production is expanding dramatically in southern Africa as mentioned in this paper, and specific varieties are inoculated with locally produced Bradyrhizobium inoculants, which nodulate and fix nitrogen well in farmers' fields with no history of inoculation in Zimbabwe, Zambia and Malawi.

Journal ArticleDOI
TL;DR: In this paper, the impact of shifting from soil ploughing to farming with reduced or zero tillage on weed communities was discussed, and the effects of cultural activities on moulding weed characteristics was also apparent.

Journal ArticleDOI
TL;DR: It is indicated that genotypes with high harvest index (HI) are likely to perform well in different fertility conditions and both N- and P-use efficiency were consistent across fertiliser levels, and hence were likely to be used as selection criteria.

Journal ArticleDOI
TL;DR: In this article, the stability of Austrian-grown quality wheats was investigated using rheological parameters from the farinogram (dough development time, stability, degree of softening) and extensogram (extensibility, maximum resistance, energy), indirect parameters (protein content, wet gluten content, Zeleny sedimentation volume, Hagberg falling number) and the loaf volume.