Nitrogen and phosphate balance on crop production in Japan on national and prefectural scales

Abstract

Trends in nitrogen (N) and phosphate (P) balance for several crops were calculated for the nation and by prefecture for 5-year periods from 1985 to 2005. Prefectural chemical N and P fertilizer applications for paddy rice and upland crops declined but applications for vegetable crops increased during the period like as national trends. Prefectural chemical N and P applications for tea, orchard and forage remained unchanged in line with national trends. Manure N and P applications for each crop did not follow the trends for chemical fertilizer. Although chemical fertilizer application declined, N and P crop withdrawal for paddy rice, upland crops and tea increased as a result of optimizing fertilizer timing and placement. Nitrogen and P balance for each crop indicated a surplus; P surplus was larger than N surplus, because of higher P input and lower crop P withdrawal. Chemical N fertilizer determined N surplus except for forage, which was determined by manure application. Therefore N surplus on paddy rice, upland crops, orchard and tea declined and increased on vegetables. Forage recorded an N deficiency in two 5-year periods nationally because of low manure input. Because P balance was also determined by chemical P fertilizer, the P surplus for paddy rice and upland crops declined and the P surplus for vegetables increased during the period. Total P surplus was reduced on paddy rice and upland crops. Trends for chemical fertilizer, manure and N and P balance varied widely among prefectures, especially for P. Crop withdrawal of N and P varied relatively little. Although prefectural trends did not always follow the national trend, we could conclude that the negative environmental effects of Japanese crop production have diminished recently, and an improvement in N and P balance in vegetable production can be expected.

Inoculation of arbuscular mycorrhizal fungi can substantially reduce phosphate fertilizer application to Allium fistulosum L. and achieve marketable yield under field condition

“…This means that the use of AM fungal inoculum is valuable for farmers. Heavy application of phosphate fertilizer has been carried out on horticultural crops (Mishima et al 2010;Reijneveld et al 2010). Rock phosphate has been used to produce phosphate fertilizers, and availability of rock phosphate may peak in about 2030 (Cordell et al 2009).…”

Effects of phosphorus-based application of animal manure compost on the yield of silage corn and on soil phosphorus accumulation in an upland Andosol in Japan

“…Mishima et al (2010) showed that the P surplus was larger than the N surplus in Japan. As a result, the concentration of available P in agricultural soil has been increasing (Obara and Nakai 2004).…”

“…As a result, the concentration of available P in agricultural soil has been increasing (Obara and Nakai 2004). Mishima et al (2010) calculated that 20% of the P applied to agricultural land was derived from animal manure, and that vegetable crops in Japan received especially large amounts of P (122 kg P ha −1 year −1 ) through animal manure amendments. Livestock manure therefore contributed significantly to the observed soil P accumulation.…”

Changes in soil available-nutrient stores and relationships with nutrient balance and crop productivity in Japan

“…In vegetables, the N balance decreased till the second survey, but showed a later increasing trend, attributable to increasing manure and chemical fertilizer N input. Mishima et al (2010b) calculated N balance on six crop groups in Japan without considering soil group, found a similar decreasing trend in N balance except in vegetables, and attributed the reduction mainly to reduced input of fertilizers. Among the Organisation for Economic Co-operation and Development (OECD) countries, an increased N balance was caused by intensification of livestock farming rather than by an increase in the application of chemical N fertilizers (OECD 2008).…”

“…Large N surpluses raise the risk of N leaching into groundwater (Nishio 2003;Mishima et al 2009). N has been especially over-applied to vegetables and tea (Camelia sinensis L.) (Mishima et al 2010b). In this paper, we assessed N and phosphate balance in six crop categories, although they cannot indicate the effect to farmland soils under different fertilization.…”