Petra Földesi

Investigation of green manuring plants as secondary crop improving unfavourable field conditions to efficient food production

Introduction During green manure application the relatively fast growing and huge yielding biomass providing plants are produced so as to get the green parts applied back into the soil by rotation (plowing) or by shallow mixing (e.g. by disc harrow or cultivator). Westsik (1965) studied green manure application of different pulses. Nevertheless there are numerous other plants involved in production for the above purpose, for example mustard, oil radish, phacelia, buckwheat, purple clover, forage radish, sweet clover, and different ration of mixture of the above plants. Production of these plants can be as a mainor as a secondary crop. The main seeding is not widely applied either in Hungary or abroad (Kahnt 1986), in Hungary there are backgrounds existing for the production of the second seeded green manure plants (Gyarfas, 1953). The green parts applied into the soil improve the physical and biological conditions and the nutrient state of the soil, contribute to increase of organic matter, protect the surface from windand water erosion. Due to the intense root development they also have a biological loosening effect in the soil decreasing this way the chance for formation of a compacted layer. Being produced the above plants as a secondary crop they reduce leaching of nutrients, mainly in very wet years. Primarily they take up nitrogen in huge amount, this way it can be utilized by the following plant directly (Birkas et al. 2002; Hansen and Djurhuus, 1997; Jamriska 2002; Sainju and Singh 1997). Some green manure plants can also be utilized to create a more diverse animal feeding. In this case specific parts of the green manure plants are chopped and fed by animals in fresh condition or as silage.

Realities and beliefs in sustainable soil tillage systems — A research approach

Results of the investigations: 1. The soil condition demand of the plants can be fulfilled in harmony with the soil quality improvement and conservation. 2. For decreasing climatic harms classical beliefs are to be supervised, e.g. fine-aggregated seedbed, surface preparation by disk on ploughed soils, summer ploughing, durability of shade/frost mellowing. 3. Some fashionable technologies are to be revised before adoption to our soils.

The effect of conventional tillage systems on soil compaction

Soil compaction is one of the major problems that modern agriculture has to deal with (Hamza and Anderson, 2004). One of the indicators of soil structure and the deterioration of soil structure is compaction, which is an obstruction of the development of favorable porosity conditions, water-air proportion and micro-biological life, which is also a condition of stable structure and mellowing (Schmidt et al., 1998). Overuse of machinery, intensive cropping, short crop rotations, intensive grazing and inappropriate soil management leads to compaction (Hamza and Anderson, 2004). Soil compaction is influenced by climate (drying/wetting, freezing/melting, moisture, evaporation) and soil (structure, clay minerals, organic matter, commutable cations, agronomical structure, original compaction, and moisture content, soil biological activity) factors as well as land use. As a result of maleficent compaction circulation of soil water, air and heat is deteriorating, microbiological functions and the activity of earthworms are slowing down, digestion of stubble remnants, manure and nutriments is decreasing, humus dissociation processes are increasing, nutrient and water absorption of plants is slowing (drought effect, damage of plants, crop yield reduction occur), energy demand of cultivation is growing, degradation processes increase (the soil becomes unprotected against erosion and deflation), the soil condition is deteriorating, the opportunity of proliferation of pests is bigger. Some forms of soil compaction effects 3.1 million hectares of arable land in Hungary (Nyiri, 1993; Varallyay, 1996; BirkAs et al., 2004). The proportion of effected areas is constantly growing since 1988, and today it already has an economic impact due to its negative effects. Soil compaction resulted by cultivation became a widespread problem in Middle-East-Europe (B irk As et al., 1996). According to the studies of BirkAs es Gyuricza (2004) half of the arable land in Hungary contains a solid plough pan in one or two depths.

Changing climate struck biodiversity in Asia and the Pacific: An overview

Two over-riding trends characterize the beginning of the third millennium. First, the global human ecosystem diversity is threatend by grave imbalances in productivity and in the distribution of goods and service. The unsustainable progression of extremes of wealth and poverty threatens the stability of the whole human system, and with it the global environment. Secondly, the world is undergoing accelerating change, with internationally-coordinate environmental stewardship lagging behind economic and social development. While each part of the Earths surface is endowed with its own combination of environmental attributes, each area must also contend with a unique, but interlinked, set of current and emerging problems. Forests, woodlands and grasslands are still being degraded or destroyed, marginal lands turned into deserts, and natural ecosystems reduced or fragmented, further threatening biodiversity (Dearden, P. 1996).