Soil organic matter pools and crop yields as affected by the rate of farmyard manure and use of biodynamic preparations in a sandy soil

Abstract

One aim of organic and biodynamic agriculture is to improve soil fertility. Our objectives are to (1) explain previously reported differences in the soil organic matter levels between soils receiving farmyard manure (FYM) with or without biodynamic preparations (BD), (2) quantify the effect of three levels of FYM applications on microbial biomass and soil organic matter (SOM) pools with different stability, and (3) relate SOM pools to crop yields in a long-term experiment on a sandy soil at Darmstadt, Germany. Soils of the BD-FYM treatments had significantly higher C org contents compared to soils of the FYM treatments. However, soil fractionation indicated that there was a greater storage of C org in the intermediate and passive pools of the BD-FYM treatments, and the temporal course of C org contents suggested a slow convergence of C org stocks between FYM and BD-FYM with time. Thus, the observed differences between BD-FYM and FYM treatments were likely to have existed since the beginning of the experiment. Contents of labile C (70-114 g [kg C org ], −1 turnover time 462 days) and labile N (35-49 g [kg N t ] −1 , turnover time of 153 days) were strongly related to the application rate and also to crop yields. Yield of potatoes, winter rye, and clover significantly increased in proportion to the application rate of FYM, while BD had no effect. Overall, the study showed that increasing rates of FYM increased C and N availability independent of the use of BD. Nevertheless, efficiency of C sequestration in a more stable form (intermediate pool) decreased with increasing rate.

Short-term residual effects of various amendments on organic C and N, and available nutrients in soil under organic crop production

“…Similarly, the highest increase in TOC and TON from compost than other amendments in our study was due to its dual effect by directly contributing to organic C and N, plus additional indirect contri ution of C from increased b crop residue (roots, stubble, straw, chaff/fallen leaves) returned to the land/soil, as evidenced by greatest increase in straw yield in this treatment [39]. Inorganic amendments usually supply specific nutrients and do not contribute directly to soil organic matter, resulting in much less contribution to soil organic C and N. Other recent research in Germany has also shown significant increase in soil organic matter after four annual applications of farm yard manure (FYM) to organic crops [7]. The relative greater increases in C or N for LFOC or LFON than TOC or TON in our study are in agreement with other research, where light organic fraction was also more responsive to management practices than total organic fraction [14][15][16].…”

“…In a growth chamber study, Qian et al [8] showed significant increase in total N in soil with application of alfalfa powder and anticipated increase in N availability to subsequent crops. In a field study in Germany, Heitkamp et al [7] found significant increase in labile N with application of FYM for four years, and the increase was strongly related to rate of FYM and also to crop yield. In another study in southern Alberta, Canada, long-term applications of cattle manure increased potentially mineralizable N and P in soil samples collected every five years over 25-year period [40].…”

“…Fertilization with organic amendments, such as compost manure/farm yard manure (FYM), alfalfa pellets/powder, distiller grain and thin stillage can have both direct (e.g., enhancing organic C in soil) and indirect (e.g., providing available nutrients after decomposition/mineralization) benefits on soil physical, chemical and biological properties, and crop yields [1][2][3][4][5][6][7][8][9]. Inorganic amendments and microbial inoculants, such as wood ash, rock phosphate, Penicillium bilaiae, MykePro, gypsum and elemental S, have been investigated for their potential as organic fertilizers in many studies, but their effectiveness to increase the availability of P or S in soil, and subsequently improve crop yield varies with nutrient source/type, severity of P, S and other nutrients deficiency in soil, soil type and climatic conditions [10][11][12][13].…”

Soil Health and Related Ecosystem Services in Organic Agriculture

“…Organic matter is the primary source of many nutrients in organic farming systems (Heitkamop et al, 2011). Retention of organic matter is essential for good management and provides other benefits to soil conditions for www.ccsenet.org/sar Sustainable Agriculture Research Vol.…”

“…Furthermore, the avoidance of loss of nutients into the surrounding environment, including loss to groundwater, is also a high priority for organic systems (Askegaard et al, 2011). The effectiveness of use of nutrients in organic farming systems depends on the rate of cycling of nutrients from both organic matter and allowable minerals, which differ in magnitude according to the soil's inherent fertility (Heitkamop et al, 2011) and mineralogical composition (van Straaten, 2002). Globally, soils used for organic agriculture range from deep, highly fertile soils to shallow, highly weathered and nutrient depleted soils (Chivenge et al, 2011).…”