Organic fertilizers derived from plant materials Part II: Turnover in field trials

Abstract

Our aim was to investigate two different organic fertilizers derived from plant materials (OFDP) with respect to their nitrogen (N) and carbon (C) turnover in field trials planted with small radish (Raphanus sativus L. var. sativus) and white cabbage (Brassica oleracea L. convar. capitata var. alba) or fallow. The two fertilizers investigated were coarse seed meal of yellow lupin (Lupinus luteus L.) and coarse meal of castor cake (Ricinus communis L.). Under cool spring conditions, the soil turnover of yellow lupin-seed meal was slightly enhanced compared to castor-cake meal. During the vegetation period of the vegetables, N added with both fertilizers was metabolized more or less completely by soil microorganisms. Due to similar efficiencies of the fertilizers tested, no significant difference could be found in the N uptake of plants. From this point of view, yellow lupin-seed meal, which can be produced by farmers themselves, has the potential to replace the widely used castor-cake meal. Considerable amounts of N may remain in the field after fertilization with OFDPs either as mineral N or as easily mineralizable organic N. This N should be utilized immediately by a succeeding crop to avoid leaching losses.Key words: castor cake / lupin-seed meal / nitrogen turnover / organic fertilizers / small radish / white cabbage

Emission of CO₂, CH₄ and N₂O and dynamics of mineral N in soils amended with castor bean (Ricinus communis L.) and piñón (Jatropha curcas L.) seed cake

“…The decomposition of JSC and RSC was high at the onset of the experiment and decreased thereafter. A larger CO 2 emission at the onset of the experiment has also been observed by Müller et al (2006), and can be attributed to the mineralization of the easily decomposable fraction, e.g. extractable polysaccharides.…”

“…As such, large amounts of the organic N in the seed cake will become available as nutrient in soil quickly (Müller et al 2006, Ramachandran et al 2007. The difference in N mineralized between the two seed cakes might be due to different factors.…”

Effects of compost, biochar and manure on carbon mineralization of biogas residues applied to soil

“…The soil was sieved through a 2-mm screen, and both soil and co-amendments were homogenized prior to incubation. To accord with earlier studies (Müller & von Fragstein und Niemsdorff, 2006;Chen et al, 2012) and agricultural practice where amendments are regarded mainly as N fertilizers, we adjusted the amount of labelled and unlabelled BGRs, compost, biochar and manure applied to the soil to correspond to 0.066 g N kg −1 dry soil each. Samples with co-amendments (BGRs + another additive) received 0.132 g N kg −1 , with a 1:1 ratio of BGRs and the other additive.…”

Changes in microbial biomass indices after 10 years of farmyard manure and vegetal fertilizer application to a sandy soil under organic management

“…The effects of plant-derived vegetal organic fertilizers have mainly been investigated for horticultural purposes, looking at the mineralization processes as a function of environmental variables often in incubation studies (Müller and von Fragstein und Niemsdorff 2006a;Stadler et al 2006;Li et al 2009;Sabahi et al 2009), pot experiments and once in a short-term field experiment with carrots and cabbage (Müller and von Fragstein und Niemsdorff 2006b). In these experiments, often legume seed grits or commercially available organic fertilizers, such as horn meal and castor cake grits, have been used, although their use for agricultural purposes is restricted due to their high price.…”