atlooalTotashWtiMe, Vrqbi tl t ri Ba %WIPS _-_ er, _e., s_, M Ferfil' N d T 9 rl T, t"jl-"r- a AL_.r ract" np 4ot Wot m of the lwennsth-6nA -P .1984, International Potash Institute Nutrient Balances and Fertilizer Needs in Temperate Agriculture fProceedings of the 18th Colloquium of the International Potash Institute held in Gardone-Riviera/Italy 1984 Contents Opening Session Page A. Malquori Introduction 9 1st Session Nutrient Balances in Farming Systems A. van Diest Characteristics of nutrient cycling and nutrient balance sheets in low-input and high-input agriculture 13 G. Toderi and G. Giordani Long-term development of soil nutrient status in an intensive cropping system 39 J. McEwen and A.E. Johnston Factors affecting the production and composition of mixed grass/clover swards containing modem high-yielding clovers 47 WE. Murphy Nutrient balances in farming systems - Intensive grassland in Northwestern Europe 63 U. Walther Nutrient balance in mixed farming sys- tems with low and high stocking rates 71 T Walsh Co-ordinator's Report on the I st Session 83 2nd Session Evaluation of Nutrient Balances H. Beringer Prospects and limitations of soil and plant analysis for establishing nutrient balances for major crops 91 R. Edelstein, Sala Feigenbaum Potassium and structural cations release and L Shainberg from micas in dilute solutions 115 J.P. Ryser Evaluation of potassium fixation and release in nutrient balances 129 5 G. Chisci and P. Spallaci Nutrient losses by leaching and run-off and possibilities of their control 137 A.E. Johnston and J. McEwen The special value for crop production of reserves of nutrients in the subsoil and the use of special methods of deep placement in raising yields 157 A. Kechl Potassium balances in a series of field ex- periments 177 A. Vez Co-ordinator's Report on the 2nd Session 187 3rd Session Building Yields by Fertilizer Input in Temperate Agricultural Systems P.B. Tinker Site-specific yield potentials in relation to fertilizer use 193 P. Sequi and P. Nannipierri Nitrification inhibitors and nutrient up- take by plants 209 K. Nemeth Response of grain yield of wheat to potassium as a function of nitrogen dynamics in the soil 217 G. Trolldenier Effect of potassium fertilizers on take-all of wheat 225 Denise Blanc The influence of mineral nutrition on plant susceptibility to pathogens 235 S.L. Jansson Co-ordinator's Report on the 3rd Session 243 4th Session Fertilizer Needs in Temperate Ecosystems J. Hebert Levels of fertilizer input and soil nutrient status in European agriculture 249 G. Droeven and L Rixhon Fertilizers, soil and crop management - Evaluation of long-term field exper- iments (1953-1983) 273 G. Thevenet Interactions between fertilizers and irri- gation with reference to nitrogen and winter wheat 291 6 H. Mantinger Fertilizer needs in fruit production 307 M. Fregoni Nutrient needs in wine production 319 0. Steineck Co-ordinator's Report on the 4th Session 333 5th Session Agricultural Productivity in Ecosystems LN. Overrein Biogeochemistry of forest ecosystems in relation to maintaining or increasing their productivity 339 K. Mengel Nutrient availability, fertilizer input and agricultural yields 349 7 Introduction A. Malquori, Chairman of the 18th IPI-Colloquium, Member of the Scientific Board of the International Potash Institute* As Chairman of this Colloquium, my first, and very pleasant, duty is to welcome you all to Gardone. We are honoured that after an interval of some years the InternationalPotash Institutedecided on Italy as the venue for the 18th Colloquium. In the early years of the Institute we were hosts in Rome for the 1955 Congress 'Potassiumin the Soil'. Later, in 1968 the Colloquium dealing with the 'Fertilization of Protected Crops' was held in Florence. The title for the current cycle of IPI's scientific colloquia is: 'Nutrient Balances and Fertilizer Needs in Different Climates" This title expresses our concern as to how much fertilizer per unit area is needed if we wish to sustain optimum plant growth now and to maintain soil fertility for the future. Essential in the nutrition of plants under natural conditions is the cycling of nutri- ents between the pedosphere, the biosphere (microorganisms, plants, animals), the hydrosphere and, to some extent, the atmosphere. Rates of nutrient transition between these must be known if the balance of nutrients is to be adequately defined from the ecological point of view. In agriculture, we, as scientists, are especially con- cerned with the soil's ability to supply nutrients to the growing crop over a growing season. Plants take up nutrients from the soil solution in which concentrations are buffered by nutrients adsorbed to clay minerals and organic matter and we might consider nutrient balance as that situation in which plant nutrients are in the equi- librium situation required for optimum growth. However, conditions can never be static owing to nutrient uptake by plants and to losses by leaching or volatilization. A useful practical approach is to consider nutrient balances over a growing season or over a rotation and so to establish balance sheets based on nutrient inputs and outputs. This 'book-keeping' approach is appropriate for planning fertilizer use on a regional or national basis. In taking the nutrient balance concept into the field we really need more detail and we have to take into account effects which the soil, the weather and the crop might have on the mobility and availability of plant nutrients. These can best be investi- gated in field experiments. The aim is to arrive at the situation where the field pro- duces economically optimum yields which can be maintained over many years and where the efficiency of fertilizer use is high. These are the aspects which will be prin- cipally discussed here, as they were in last year's Colloquium in Morocco dealing with arid and semi-arid climates and will be next year in a tropical environment. We have five working sessions: 1) Nutrient balances in farming systems, 2) Evalu- ation of nutrient balances, 3) Building yields by fertilizer input in temperate agricul- tural systems, 4) Fertilizer needs in temperate eco-systems, 5) Agricultural productivity in eco-systems. When the lectures and discussions are finished, the excursions will allow you to see something of specialized agriculture in the region. * Prof. Dr. A. Malquori, Istituto di Chimica Agraria e Forestale, Facolt. di Agraria, Piazzale Cascine 28, 1-50100 Fireaze/Italy 9 The choice of northern Italy to represent the temperate zone places our Colloquium in the centre of a type of agriculture which can be considered advanced in its control of soil fertility, in the use of selected crop varieties and which is highly productive both in general farming and in highly specialized enterprises. Touching the soils of this region which have been cultivated over so many generations, it is interesting to remark that in his first report on Italy, Bonaparte described the plains of northern Italy as being among the most fertile in the world. The propitious natural conditions have favoured the development of industry and in some regions such as Piedmont, Lombardy, Venetia and Emilia excellent relations have been established between agriculture and industry. I am sure that the results which will be presented here and the discussions we shall have will contribute conspicuously to the perfection of fertilizer use in the temperate area and that this will in turn be evidenced by a further improvement in agricultural production in both quantitative and qualitative terms. We should never forget that the main problem which agriculture has to face is the constant growth in world population; there is no doubt that fertilizers have a key role to play in solving this problem. I am glad that you are all able to take part in this Colloquium. Knowing the standing of our speakers, I am sure you will find your participation to be fruitful. I wish you all a pleasant stay on the shores of this beautiful lake which has something to offer to everyone and which was found so congenial by Catullus, Virgil, Dante and Goethe. 10 Chairman of the 1st Session Dr. T Walsh, former Director of the Institute of Agriculture of Ireland, Dublin/Ireland; mem- ber of the Scientific Board of the International Potash Institute 1st Session Nutrient Balances in Farming Systems Characteristics of Nutrient Cycling and Nutrient Balance Sheets in Low- Input and High-Input Agriculture A. van Diest, Department of Soid Science and Plant Nutrition, Wageningen Agricultural Uni- versity/Netherlands*; Member of the Scientific Board of the International Potash Institute Summary Nutrient cycles for the elements N, P, and K were considered. It was shown that for all three nutrients the cycles can be divided into subcycles. For each cycle, in one of the subcycles the nutrient involved is channeled toward the crop that is grown. The other subcycles act as com- petitors with the crop for the nutrient. In the case of N, microorganisms and the atmosphere are the main competitors. For P, the soil is the primary competitor with microbes taking a sec- ond position. For K, surface water and the oceans are competing with higher plants, while under certain conditions the soil can be a strong competitor. To maximize the efficiency of utilization of nutrients applied as fertilizers, care should be taken that the general growing conditions allow a crop to compete as effectively as possible with other agents in the various nutrient cycles for the nutrient involved. The examples shown in this paper make it clear that the degree of recovery of a fertilizer nutrient is usually a func- tion of the quality of the growing conditions and also of the type of farming, but not of the quantity of the nutrient applied as long as the quantity is adjusted to the need of the crop grown.