Title: Impact of Mineral Fertilizer Integration with Farmyard Manure on Crop Yield, Nutrient Use Efficiency, and Soil Fertility in a Long-Term Trial
Abstract: systems must be replaced so that soil fertility is not depleted over time: and at the same time, excess nutrient accumulation must be avoided to reduce the risk of nutrients moving out of the root zone to the air and water (Aulakh and Grant, 2008).Management of plant nutrient can potentially address the challenge through soil fertility improvement and reduction of nutrient loss.Soil fertility is the capacity of a soil to retain, cycle and supply essential nutrients for plant growth over extended periods of time (Alley and Vanlauwe, 2009).Nutrient and organic matter content of the soil determines status of its fertility.Soil organic matter is an important index of soil fertility (Rahman and Parkinson, 2007).It improves soil fertility with the following functions: source of inorganic nutrient for crops and microbial biomass, exchange of ions, chelating agent and buffer, aggregating soil particles, support root development, and water conservation (Allison, 1973).In addition, it reduces level of atmospheric CO2 that contributes positively to climate change (USDA and NRCS, 2003).The concept of IPNM primarily optimizes the use of nutrients in organic fertilizer to maximize crop yield per area and to improve nutrient use efficiency (NUE) synergistically.Improvement of NUE implies reduction of nutrient losses so that it indicates environmental impact of nutrient management.NUE in agriculture can be considered from three major perspectives: (i) as 跨agronomic efficiency誇 that concerns optimization of nutrient uptake by crop; (ii) as 跨economic efficiency誇 that implies improvement of nutrient input increases profitability of crop production; and (iii) as 跨environmental efficiency誇, i.e. minimization of losses of nutrient to the environment (Robert, 2005).There are different methods to express NUE.This study uses the 跨difference method誇, i.e. total nutrient removal of fertilized crop minus total nutrient removal of unfertilized crop per fertilizer rate (Varvel and Peterson, 1990).It is appropriate to use the method in the long-term trials because nutrient is residually accumulated each year.This paper analyzes a long-term agronomic field trial comparing different schemes of integration of mineral fertilizer with Farm Yard Manure (FYM) in the production of potato, rye, and oat from 1958 -2008.The objective of the trial is to measure the effects of IPNM on economic, social, and environmental dimensions of crop production sustainability.Moreover it investigates whether organic or mineral fertilizer alone can sustain nutrient demand of crop at the right balance to achieve the highest yield.It evaluates benefits of supplementing organic with mineral fertilizer and balanced mineral fertilizer application in crop production compared to application of organic fertilizer alone.Nutrient management affects ability to maximize crop yield per area, which is a primary factor to produce sufficiently high quality food, feed, and fiber in economically viable systems of production.There are three major components of plant nutrient managements, which are known as nutrient recycling or organic plant nutrient management (OPNM), IPNM, and balanced plant nutrient management (BPNM).In this study the three components of plant nutrient managements are considered as FYM alone (OPNM), FYM + mineral fertilizer (IPNM), and mineral N+PK+Mg fertilizers alone (BPNM).The analysis deals with the evaluation of social and economic (crop yield), environmental (NUE), and soil fertility (organic matter and nutrient index) benefits of the IPNM and the BPNM compared to the OPNM. Material and methods Location and historyThe Hanninghof long-term trial is located near Duelmen in Western Germany.The experiment started in 1958 with potato cultivation.The potato was followed by winter rye in 1959 and oat in1960.Since then each crop was cultivated 17 times in rotation.Long