• Authors:
    • Rashakani, M. A.
    • Robati, J.
    • Germi, Y. S.
  • Source: Proceedings 37th International Symposium 'Actual tasks on agricultural engineering', Opatija, Croatia, 10-13 veljače, 2009
  • Year: 2009
  • Summary: Applying the precision planters such as punch planters is one of the methods for increasing yield performance by retaining the conservation tillage advantages. In this study, a type of dibble punch planter with seed plate metering device was designed and constructed for maize planting, and was tested in the field on three soil conditions (tilled, untilled with no residue, untilled with wheat residue) and at three forward speeds (1.5, 3, 4.5 km h -1). Then, the planter performance was evaluated with quality of feed index, miss index, multiple seed index, depth index and radius of contact cross section area in the field. Field test results showed that the second speed (3 km h -1) has relatively higher feed index. The difference of feed index was not significant between tilled soil and untilled soil (with residue) and also between v1 and v2. Also, the difference between the different levels of soil conditions and forward speeds was significant (p
  • Authors:
    • Wasaya, A.
    • Asif, M.
    • Tanveer, A.
    • Nadeem, M. A.
    • Tahir, M.
    • Ali, A.
    • Jamil-ur-Rehman
  • Source: Pakistan Journal Of Life and Social Science
  • Volume: 7
  • Issue: 2
  • Year: 2009
  • Summary: In field experiment at Faisalabad, Pakistan conducted during August, 2005, the effect of different irrigation management strategies on growth and yield of soybean was investigated. The experiment comprised of eight irrigation practices of viz; rainfed, one irrigation at vegetative growth stage, one irrigation at flowering, one irrigation at pod formation, two irrigations at vegetative growth stage and at flowering, two irrigations at vegetative growth stage and at pod formation, two irrigations at flowering and at pod formation and three irrigations at vegetative growth stage, at flowering and at pod formation. Number of plants m -2, number of pods per plant, number of seeds per pod and seed yield was significantly higher when crop was irrigated with three irrigations at vegetative growth stage, at flowering and at pod formation.
  • Authors:
    • Smith, H. J.
    • Trytsman, G.
    • Bloem, J. F.
  • Source: Biological Nitrogen Fixation: Towards Poverty Alleviation through Sustainable Agriculture
  • Volume: 48
  • Issue: 1-3
  • Year: 2009
  • Summary: Farm lands of resource-poor communities in South Africa are depleted of nutrients due to continuous mono-cropping, limited use of fertilisers, and sometimes leaching caused by high rainfall. Despite the well-known advantages of biological nitrogen fixation (BNF) in cropping systems, less than 10% of the grain crops planted annually in these areas are legumes. Using a participatory research and development approach, resource-poor farmers were introduced to conservation agriculture (CA) practices, including BNF, that promoted zero (or reduced) tillage, increased retention of soil cover, as well as crop diversification. Because crop rotation and intercropping of legumes with cereals are known to contribute to soil fertility while enhancing food security, resource-poor fanners from various Provinces in South Africa were trained on the benefits of legume culture for eight years. As a result, these resource-poor farmers did not only get training in inoculation techniques, but were also supplied with inoculants for use on their farms. Data collected from Farmers Demonstration Trials at Belvedere, Dumbarton and Lusikisiki, showed that the grain and fodder yield of maize planted after legumes, and maize intercropped with legumes, were comparable to those of maize receiving high N fertilizer dose (i.e. 54 kg N at planting and 54 kg N as top-dressing). The same data further showed that Rhizobium inoculation, when combined with application of low levels of P and K. significantly increased crop yields within farmers' trial plots. BNF therefore offers a great opportunity for resource-poor farmers in South Africa to increase their crop yields and thus improve the quality of their livelihoods through the adoption of affordable and sustainable biological technologies that enhance soil fertility.
  • Authors:
    • Jia, H.
    • Chen, Z.
    • Ma, C.
    • Yang, Q.
    • Liu, Z.
    • Li, G.
  • Source: Nongye Jixie Xuebao = Transactions of the Chinese Society for Agricultural Machinery
  • Volume: 39
  • Issue: 11
  • Year: 2008
  • Summary: This paper describes the tillage technologies for the tillage system of soil water storage and preservation in the area of dry farming of northern China, with surface mulching, reduced-till and no-till as the core technologies, based on combined operations, to achieve the goal of soil water storage and preservation and improving soil fertility. It summarizes six innovative technologies involving the combined stalk and stubble management technology, in which the stalk and stubble of corn can be broken and partially buried in soil at one time; the universal technology for rototilling and stubble breaking, in which the two operations, can be done on the same blade rotor and disc; the strip reduced-till (no-till) precision seeding technology, in which less-tillage (or only furrowing) is needed in the seed bed; the ridging and film-side furrow sowing technology, in which the ridge is covered with the film and seeds are sowed in the furrow; the mechanical bionic resistance reduction technology, which uses the soil working tool designed based on bionics; and the no-till planting and blockage prevention technology, in which no-till planting is conducted in the residue free seed bed. It also shows the composition diagram of the farming system.
  • Authors:
    • Wang, Z.
    • Hao, M.
    • Wang, L.
    • Li, S.
    • Li, X.
  • Source: Scientia Agricultura Sinica
  • Volume: 41
  • Issue: 9
  • Year: 2008
  • Summary: Objective: Research on effects of monocropping or rotation of different crops on water and different forms of soil organic nitrogen (N) and mineral N in dryland soils is recognized to be of great significance in determining dryland crop sequences, increasing soil fertility, and optimizing nutrients management. Method: Dryland soil samples were taken from 6 cropping systems: fallowing, continuous wheat monocropping, continuous maize monocropping, continuous alfalfa cropping with no-till, pea-wheat-wheat-millet rotation and maize-wheat-wheat-millet rotation, from a 23-year long-term experimental site on the Loess Plateau, to study the effects of cropping systems on soil water, organic N, light fraction organic N and mineral N. Result: Results obtained showed that continuous long-term fallowing system contained the lowest organic N, light fraction organic N and mineral N. Long-period alfalfa cropping with no-till system could promote water storage in topsoil layers, and accumulation of organic and light fraction organic N in 0-20 cm soil layers, but increased exhaustion of water and mineral N in deep soil layers. Continuous monocropping of wheat or maize could all significantly increase soil organic and light fraction organic N contents, and the organic N were increased more by monocropping of wheat. Organic N contents in soil layers of two rotation systems showed no obvious different to monocropping of wheat. Light fraction organic N contents also were not obvious different between two rotations in 0-20 cm soil layers, but they were all significantly higher than wheat or maize monocropping. The amount of soil mineral N was found to depend on the status of crop growing or N fertilizer application at sampling time. Conclusion: Although long term monocropping of legumes without tillage can enhance organic N accumulation by increase the light fraction organic N in soil, the exhaustion of soil water in deep layers is also increased. Rotations of legumes with cereal crops or the shallow and deep root crop rotations are proved to be feasible measures to optimize soil water utilization, increase organic N accumulation in soil, and synergize soil N supply capacity.
  • Authors:
    • Rani, K. U.
    • Madhavi, M.
    • Ramesh, G.
    • Sankar, G. M.
    • Ravindrachary, G.
    • Adake, R. V.
    • Grace, J. K.
    • Korwar, G. R.
    • Mishra, P. K.
    • Srinivas, K.
    • Mandal, U. K.
    • Jain, P. M.
    • Jat, M. L.
    • Kothari, A. K.
    • Laddha, K. C.
    • Sharma, K. L.
  • Source: Indian Journal of Dryland Agricultural Research and Development
  • Volume: 23
  • Issue: 1
  • Year: 2008
  • Summary: Rainfed soils of Arjia region, Gujarat, India, which are under maize based production system, are damaged due to several soil related productivity constraints such as loss of topsoil causing severe soil erosion. The yield levels of majority of the crops grown in these soils are low. Soil quality deterioration has been the major bottleneck in realizing the higher levels of crop yields in this rainfed region. Hence, there was a need to identify and adopt appropriate soil and plant management practices that reduce soil degradation or maintain and improve soil quality at a desirable level. In view of the above, a long-term experiment was adopted for assessing soil quality as influenced by different soil-nutrient and other management practices followed at All India Coordinated Research Project for Dryland Agriculture centre of Arjia. Soil samples were analysed for 19 physical, chemical and biological soil quality parameters and soil quality indices were worked out using deviation method. From the viewpoint of soil quality improvement or soil aggradation, combination of conventional tillage + 2 weedicides + hoeing + 100% organic N ranked as superior among most treatment with the relative soil quality index value as high as 0.95 under maize-blackgram system. Further, cropping systems adjoining to the experimental station were also evaluated for soil quality. In the farmers' fields, the order of the systems in aggrading soil quality was as: maize-blackgram (1.00) > groundnut-sesame (0.75), > groundnut-taramira (0.72). The full paper deals in length about the extent and magnitude of changes in soil quality parameters and relative soil quality indices.
  • Authors:
    • Nayyar, A.
    • Bijay, S.
    • Humphreys, E.
    • Brar, N.
    • Yadvinder, S.
    • Timsina, J.
  • Source: ACIAR Proceedings Series
  • Issue: 127
  • Year: 2008
  • Summary: Rice-wheat (RW) is the dominant cropping system in north-western India and is of immense importance for national food security. However, the sustainability of the RW system is threatened by water shortage and nutrient mining. Permanent bed RW systems with crop residue retention have been proposed as a means of reducing irrigation water use, improving soil properties and reducing the cost of crop establishment. A field experiment was conducted over 4 years in Punjab, India, to compare conventional and permanent bed RW cropping systems, with and without retention of crop residues, in terms of crop performance and nitrogen use efficiency (NUE). Two methods of rice establishment (transplanting and dry seeding) were included on both beds and flats with four N application rates (0, 80, 120, 160 kg N/ha). Rice grain yield increased significantly as N rate increased up to 160 kg N/ha irrespective of method of rice establishment. Puddled transplanted rice (PTR) was always superior to all other establishment methods in terms of biomass, yield and NUE. At 120 kg N/ha, yield of transplanted rice on permanent beds (TRB) was 29% lower than yield of PTR, while yield of direct-seeded rice on permanent beds (DSRB) was even lower (44% lower than yield of TRB). Wheat straw mulch further reduced yield of DSRB by 26% on average, but there was no effect of mulching on yield of TRB. Dry-seeded rice on flats and beds was prone to severe iron deficiency and root nematode infestation. Yield of DSRB relative to yield of PTR declined as the beds aged but there was no trend in relative yield of TRB. Recovery of fertiliser 15N in the straw plus grain was 30% in PTR compared with 14% for TRB and 17% for DSRB. The majority (65-83%) of the crop N uptake was derived from the soil in all treatments despite the application of urea at 120 kg N/ha. Total N losses from the urea N applied to rice ranged from 52% to 60% in TRB and DSRB compared with 38% in PTR. Wheat yield increased with N rate up to 120 kg N/ha, with further significant response to 160 kg N/ha in 2 of the 4 years. Wheat grain yield on permanent beds after TRB and DSRB was 75-96% of that of conventionally tilled wheat (CTW), with no trend in relative yield over time as the beds aged. Grain yield of wheat was similar in CTW and direct-drilled ('zero-till') wheat (DDW) on the flat. The 15N recovery in the wheat plants in all flat and bed treatments was similar. Straw mulch had no effect on yield or NUE of wheat. Recoveries of applied N in the wheat plants (27-38%) and soil (45-59%) were much higher than in rice. Total fertiliser N losses were much lower in wheat (mean 14-21%) compared with rice (mean 38-60%). After eight crops, soil organic C, total N and available K were significantly higher with straw mulch compared with no mulch. Permanent beds for RW seem to have limited potential under the soil and climatic conditions of Punjab, India, with current technology, even with full residue retention for both crops. Further research on permanent raised beds should focus on selection of rice and wheat cultivars that are better suited to beds; soil health issues such as nematodes and iron deficiency; weed control; N, water and residue management; and machinery development and practices.
  • Authors:
    • Fourie, J.
    • Addison, P.
  • Source: South African Journal of Enology and Viticulture
  • Volume: 29
  • Issue: 1
  • Year: 2008
  • Summary: This study was conducted as part of a larger investigation into the effect of management practices on selected sown cover crops and the effects thereof on grapevine performance. The aim of this study was to determine the effect of these cover crops on plant parasitic nematode populations under natural field conditions. The trial site was in an own-rooted Sultanina vineyard situated in the Lower Orange River of the Northern Cape Province. Three management practices were applied selectively to ten cover crop species, with two control treatments consisting of weeds. Nematodes were monitored for a period of four years. 'Saia' oats were indicated as being poor hosts to both root-knot and root-lesion nematodes, while 'Overberg' oats showed poor host status against ring nematodes. 'Midmar' ryegrass and 'Paraggio' medic were also poor hosts for root-knot nematodes, while grazing vetch appeared to be a good host for root-knot nematodes. The most notable result from this study was the relatively high numbers of all three nematodes on the vine row, as opposed to the inter-row where cover crops were established. This indicates that vines were much better hosts for these nematodes than the cover crops. It is recommended that if more definite trends are to be observed, Brassica species, which have direct toxic/repellant effects on nematodes, should be tested.
  • Authors:
    • Aarndt, S. K.
    • Eckard, R.
    • Livesley, S. J.
  • Source: Plant and Soil
  • Volume: 309
  • Issue: 1-2
  • Year: 2008
  • Authors:
    • Place, F.
    • Ajayi, O. C.
    • Akinnifesi, F. K.
    • Sileshi, G.
  • Source: Plant and Soil
  • Volume: 307
  • Issue: 1-2
  • Year: 2008
  • Summary: A number of studies have tested the effect of woody and herbaceous legumes on soil fertility and maize yields in sub-Saharan Africa. However, their effects on maize productivity are much debated because results have been variable. A meta-analysis was conducted with the aim of evaluating the evidence in support of yield benefits from woody and herbaceous green manure legumes. A total of 94 peer-reviewed publications from West, East and southern Africa qualified for inclusion in the analysis. Maize yield from herbaceous green manure legumes (54 publications), non-coppicing legumes (48 publications), coppicing woody legumes (10 publications), natural fallows (29 publications), and fully fertilized monoculture maize (52 publications) were compared. Mixed linear modelling using yield differences (D) and response ratios (RR) indicated that the response to legumes is positive. The mean yield increase (D) over unfertilized maize was highest (2.3 t ha-1) and least variable (CV=70%) in fully fertilized maize, while it was lowest (0.3 t ha-1) and most variable (CV=229%) in natural fallows. The increase in yield over unfertilized maize was 1.6 t ha-1 with coppicing woody legumes, 1.3 t ha-1 with non-coppicing woody legumes and 0.8 t ha-1 with herbaceous green manure legumes. Doubling and tripling of yields relative to the control (RR > 2) was recorded in coppicing species (67% of the cases), non-coppicing legumes (45% of the cases), herbaceous green manure legumes (16% of the cases) and natural fallows (19% of the cases). However, doubling or tripling of yields occurred only in low and medium potential sites. Amending post-fallow plots with 50% of the recommended fertilizer dose further increased yields by over 25% indicating that legume rotations may play an important role in reducing fertilizer requirements. Except with the natural fallow, the 95% confidence intervals of D and RR were higher than 1 and 0, respectively indicating significant and positive response to treatments. Therefore, it is concluded that the global maize yield response to legumes is significantly positive and higher than unfertilized maize and natural vegetation fallows.