Evaluating trends in yield and soil quality over 30 years of organically managed grass-clover ley in Norway

The article describes comparison of soil fertility indices (SFI) calculated for the ploughed layer of arable soils differing in soil organic matter (SOM) content: with high (5-8%) and medium (3-5%) SOM content. The studied soils were located on erosion-prone slope at different altitudes: soils with high SOM at 280-310 m, and soils with medium SOM at 190-280 m a.s.l. The study area was located in the interfluve area between the Irba and the Hiruzovka rivers in the Cis-Salair drained plain in the south-east of West Siberia. The soil types common there are Greyzemic Luvic Chernozems (Siltic, Aric, Pachic), Phaeozems (Siltic, Аric), Greyzemic Phaeozems Colluvic (Siltic, Taptomollic). The SFI were calculated in two steps. First, the relative indices (RI) for every agrochemical property, i.e. pHKCl, SOM, acetic acid extractable phosphorus (P) and exchangeable potassium (K), were calculated on the basis of respective minimal and optimal soil concentrations and crop requirements. Second, the SFI were calculated as sums of the relative indices divided by 4. The resultant SFI values were rated according to the scale where values below 0.4 indicate low fertility; values ranging 0.41-0.60 indicate moderate fertility, whereas values ranging 0.81-1.0 indicate high fertility. The digital maps of the RI and SFI were created using raster calculator in ENVI software, which allows performing mathematical operations with quantitative parameters of raster image pixels in GeoTIFF format. The values of relative indices in raster cells exceeding 1 (that is when factual content is higher than the optimal one) were substituted with 1 by specially developed program called ZChanger. Then the SFI map was created for erosion-risky slopes using as a basis the digital maps of the relative indices for pHKCl, SOM, P and K. Phosphorus was extracted by two different extragents, namely 0.5 М acetic acid (PAA) and 0.1 М ammonium malate (PAM). Soil fertility index was rated as medium irrespective of SOM content and soil type due to the high PAA content in soils with less SOM. It was found that when SFI were calculated using the data on easily available soil P, i.e. extracted with 0.015 М К2SO4 (PPS), then for most of the study area SFI can be rated as low, indicating the deficit of plant available phosphates in soils. High- and medium-SOM soils did not differ in рНKCL and PPS. The medium-SOM soils, such as agrochernozems, agro-grey and agro-dark-grey ones, had 1.7-2.2 lower SOM content as compared with the high-SOM soils such as agrochernozems. The reverse relation was found in labile P content: in soils with medium SOM level the PAA and PAM contents were 2 and 1.3 times higher than in high-SOM soils, respectively. In high-SOM agrochernozems PAA was lower than the optimal level (<20mg/100 g soil), while in medium-SOM soils it was higher. The PAM could be rated as medium. Exchangeable K in the arable soils was found to be unevenly distributed: in medium-SOM agrochernozems and agro-dark-grey soils exchangeable K was on average 1.2 times lower as compared with high-SOM agrochernozems, the difference with medium-SOM agro-grey soils being statistically not significant. Overall exchangeable K was lower than the optimal level (<30mg/100 g soil) Above-ground phytomass was found to be positively correlated with soil labile PPS (rs=0.41) and PAM (rs=0.33). The difference in aboveground phytomass produced by oats and peas mixture between high- and medium-SOM soils was not statistically significant.

Abstract. Knowledge of the status and influential factors of soil nutrients including soil organic matter (SOM), nitrogen (N), potassium (K), phosphorus (P), and acidification is the basis for sustainable management of tea plantations and thus the sustainability of the tea industry. However, a national-level study addressing this topic is lacking. Thereby, we assessed the status, spatial variations, and influential factors of soil nutrients and acidification in China's tea plantations based on 1843 datasets collected from 379 published articles. The results showed that only 40.9 % of the observed tea plantations meet the standards of high-quality tea plantations. Most tea plantations were facing soil acidification, nutrient deficiencies, and imbalance. Furthermore, the status of soil nutrients and pH varied among cultivation zones due to the impacts of location, climate, and soil type. Specifically, tea plantations in the southern zone showed the lowest concentrations of available N, available K, and total K but the highest stoichiometric ratios of soil nutrients (P &lt; 0.05). Management practices (e.g., rotational cycle and fertilization strategies) also significantly shaped the status of soil nutrients and pH. Therefore, applying organic fertilizer, extending the duration of the cultivation cycle, and planting shading trees were recommended to improve soil nutrient availability and balance, as well as to mitigate soil acidification. Specifically, it is recommended to apply K fertilizer to tea plantations in the southern zone and/or at high altitudes.

Organic fertilizers offer several advantages over chemical fertilizers and are an environmentally friendly alternative that could help sustainably farmed land. Reviewing indigenous knowledge of the agronomic applications of organic manure and its possible contribution to agricultural growth was the goal of this article. It is evident that organic manures from various plant and animal sources can be used to satisfy certain field needs. However, the use of organic manures is still primarily conventional since they have not been well received by agricultural strategies. When bulky organic manures are directly applied to soil, they accelerate mineralization and reduce the rate at which nutrients, especially nitrogen, are released. Compared to raw resources, which have limited value and certain disadvantages, composting these wastes appears to offer significant potential. The majority of researchers verified that adding compost might enhance the soil's organic matter content, nutrient status, and physical, chemical, and biological properties. Soil organic matter concentrations rise in every long-term compost treatment study. But since they contain more stable carbon than fresh or immature composts, mature composts raise Soil organic matter considerably more effectively. Furthermore, because compost has so many beneficial effects on the physical, chemical, and biological aspects of soil, it helps to stabilize and improve crop quality and yield. As a result, the majority of studies have demonstrated that compost has an equalizing influence on seasonal and annual variations in soil temperature, air, water, and plant nutrient availability, as well as crop yields. mostly due to the nutrients' gradual release and availability in compost-combined fertilization techniques, which frequently yield positive outcomes. Therefore, composting can be a useful choice for building effective plant-nutrient management methods in many settings for sustainable agricultural systems within small-scale farming in impoverished nations.

A well-recognized soil quality indicator is soil organic matter (SOM) content (SOMC), a soil component upon which agroecosystems and agricultural production are dependent. Agricultural practices greatly influence SOMC (Larson and Pierce, 1994) and SOMC affects crop production (Guernsey et al., 1969). Research has shown positive relationships between increased SOMC and appropriate management practices with organic carbon added to the soil (Peterson et al., 1998; Robinson et al., 1996). Removing residues increases soil erosion losses (Gupta et al., 1979), and residue harvest removes with it plant nutrients that must be replaced with fertilizer (Rasmussen and Rode, 1988) or manure applications (Sommerfeldt et al., 1988). Even with these negative impacts, it seems residues, or part of the residues, can be removed from selected soils without decreasing soil quality if appropriate management practices are used, i.e., reduced tillage, manure application, and crop rotations (Havlin et al., 1990). These practices are known to attenuate the effect of residue removal. Stevenson (1965) reported that rotations including legumes maintained a higher SOM level than continuous cropping with no leguminous crops. Few studies have explicitly measured the effect of com (Zea mays L.) residue removal on soil organic carbon (SOC; SOC = 1.6 x SOM). Karlen et al. (1994) found that normal and doubled residue addition treatments resulted in higher SOMC than the residue removal treatment within no-till continuous com in Iowa. Changes in SOMC occur slowly over periods of decades so long-term experiments are necessary to measure these changes. However, no SOMC analysis of long-term experiments designed to evaluate the effects of residue removal on SOMC when using a variety of crop and soil management practices has been located. Understanding the net effect of management alternatives on SOMC with residue removal, and the soils for which they will best work, requires research. The objective of this study is to evaluate impacts of manure and mineral fertilization application and crop rotations on soil carbon change when crop biomass is incorporated vs. when it is removed.

Organic manure induced soil food web of microbes and nematodes drive soil organic matter under jackfruit planting

&amp;lt;p&amp;gt;The aim of this study was to evaluate the effects of long-term application of exogenous organic matter on soil organic matter and water storage. Addition of organic matter is of importance in sandy soils that are in general poor in organic matter, acidic, conducive to drought and used in agricultural production throughout the world. In this study the sandy podzol (63-74% sand) was amended with chicken manure or waste spent mushroom substrate through more than 20 years. Soil organic matter content, water retention curves, acidity and structural stability were determined at three depths in the top 60 cm in organic amended and control plots. Enrichment of the soil with chicken manure and spent mushroom substrate caused increase in soil organic matter content in the top 0-20 cm from 1.34 to 3.50% and from 0.86 to 4.71%, respectively. Corresponding increases in field water capacity were from 13.6 to 31.8 m&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt; m&amp;lt;sup&amp;gt;&amp;amp;#8722;3&amp;lt;/sup&amp;gt; and from 17.7 to 27.2 m&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt; m&amp;lt;sup&amp;gt;&amp;amp;#8722;3&amp;lt;/sup&amp;gt;. Both amendments improved soil structure, reaction and nutrient status. In general, these positive effects were greater in chicken manure than spent mushroom substrate amended soil and less pronounced at depths 20-40 cm and 40-60 cm compared to upper soil. Increase in the field water capacity and water storage capacity made the soils amended with&amp;amp;#160; organic matter more drought resistant. Our findings provide valuable insights the spent mushroom substrate left after growing the mushrooms and chicken manure are environmentally friendly and economical viable soil management practices to increase soil quality and crop productivity.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;amp;#160;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;amp;#160;Acknowledgements&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The work was partially funded by the HORIZON 2020, European Commission, Programme: H2020-SFS-4-2014: Soil quality and function, project No. 635750, Interactive Soil Quality Assessment in Europe and China for Agricultural Productivity and Environmental Resilience (iSQAPER, 2015&amp;amp;#8211;2020).&amp;lt;/p&amp;gt;

ContextOrganic dairy farms with grass-clover often have a large N surplus, due to biological N fixation and in addition, manure application, which challenges the efforts to reduce N losses. Potential loss pathways include leaching from grass-clover ley and subsequent crops, but if managed appropriately this N legacy effect may result in higher yields in the subsequent crops. ObjectiveTo investigate the fate of the ley phase N surplus including losses of nitrate in grass-clover leys, contribution to the N supply of the subsequent crop, and the contribution from the long-term slurry N application to grass-clover leys to nitrate leaching and yields in subsequent crops. MethodsWe quantified nitrate leaching across three years in two six-year crop rotations with two or four years of grass-clover ley and examined legacy effect of the grass-clover ley in relation to short- or long-term N fertilization levels. This was done by measuring water nitrate contents below the root zone combined with water balance modelling. ResultsNitrate leaching in 1- to 4-yr-old grass-clover leys were not influenced by cattle slurry application of up to 300 kg total-N ha-1 (equivalent to approximately 170 kg available N). Leaching losses were 2 - 19 kg N ha-1 yr-1 across grassland ages and application rates. Arable crops showed correspondingly low nitrate leaching (4–24 kg N ha-1 yr-1) except for barley/peas (74 kg N ha-1 yr-1), where a catch crop was established after autumn mechanical weed control. The legacy effect of fertilization on N yield was found in the first year following cultivation of 2-yr-old grass-clover swards and in both year one and two following cultivation of 4-yr-old grass-clover swards. The legacy effect was generally better predicted by the long-term cumulated fertilizer N application during the last rotation (six years) as compared to the most recent grass-clover N application rate. Nitrate leaching in the arable phase of the mixed crop rotations was not affected by fertilizer application in the ley phase. However, this might depend on catch crop strategy in the arable crops. ConclusionsNitrate leaching in dairy crop rotations was not influenced by cattle slurry application. It was found that both the short- and long-term slurry application history were able to explain the legacy effect and of those, the long-term was the best predictor. ImplicationsThe study shows that N leaching reduction targets can be met in an organic dairy crop rotation when attention is paid to the full crop rotation and utilization of short- and long-term legacy effects of slurry application.

Renewable energy in the form of biogas can be produced by anaerobic digestion (AD) of animal manure. However, there is still a lack of knowledge on the long-term effects of AD-treated manure on soil characteristics and crop productivity, compared with untreated manure. A field experiment was established in a perennial grass-clover ley in 2011 to study the effects on important soil and crop characteristics when the slurry from a herd of organically managed dairy cows is anaerobically digested. While the rate of manure application affected soil concentrations of extractable nutrients and pH, these variables were unaffected by AD. Soil organic matter (SOM) concentrations decreased in all plots and faster on the plots with high intrinsic SOM. The decrease was similar with application of untreated (non-digested) slurry (US) and anaerobically digested slurry (ADS), and it was not affected by application rates. The general decline may be explained by the initial high SOM content, the long-term effect of drainage, and higher temperatures with climatic change. US and ADS gave similar yields of grass-clover ley (2 cuts/year) and green fodder, on average 0.79 and 0.40 kg DM m−2, respectively. Clover yield was similar in manured treatments and the non-fertilized control. With respect to crop yields and chemical soil characteristics, long-term (10 years) effects of AD in an organic dairy cow farming system seem to be minor. The benefits of extracting energy from the slurry did not compromise grassland productivity or soil quality in the long term.Graphical

Land-use type has a strong impact on soil organic matter (SOM) content which shows higher level in permanent grasslands than in arable lands. The inclusion of temporary grasslands in crop rotation is an efficient practice to limit SOM loss in arable lands. Nonetheless, temporary grasslands can be seen in competition with food-production for human consumption as they produce forage to feed livestock.In a context of agricultural specialization and reduction of animal-based protein consumption, it is imperative to evaluate the impact of a decrease of temporary grasslands and their frequency in crop rotation on SOM content. Moreover, it is crucial to assess if the decrease of temporary grasslands frequency, SOM content and soil quality is a linear process or if an optimum exists that maximize soil quality while minimizing temporary grasslands in the rotation.Here, we used a 40-year-old soil monitoring network in South-West Switzerland (FRIBO Network) to assess the relationship between temporary grasslands frequency, SOM loss and soil quality. Soil organic carbon (SOC) dynamics was estimated by sampling the monitoring sites every 5 years. SOC stocks were measured down to 50 cm depth. Permanent grasslands were used as reference for estimating SOM loss, controlling for variations in soil characteristics (e.g., clay, pH) and site characteristics (e.g., altitude, precipitation, crops type) among sites. The SOC-to-clay ratio was used as indicator of soil quality.Our results showed that SOM loss is proportional to the decrease of temporary grasslands frequency so that any change of frequency has the same consequence on SOM loss independently from the absolute frequency of the temporary grasslands. This suggests that there is not an optimal frequency of temporary grasslands in a soil C sequestration perspective. This contribution, however, will also show that soil quality indictors related to SOM such as the SOC-to-clay ratio exhibits thresholds that enable to define an optimal frequency of temporary grasslands in order to maintain a level of soil quality that minimizes the negative impacts on soil functioning. Hence, providing a decision framework to target agricultural fields where temporary grasslands should be promoted or could be reduced with less impact.

Impact of long-term N fertilisation on CO2 evolution from old and young SOM pools measured during the maize cropping season

To mitigate the issues of soil quality degradation and environmental pollution caused by excessive fertilizer use in apple orchards, the present study investigated the effects of organic fertilizer substitution combined with chemical nitrogen (N) fertilizer reduction on soil nutrient status, enzyme activity, and microbial communities (bacteria, fungi and archaea) over one year in an apple orchard. Five fertilization treatments were implemented, including 100% chemical fertilizer (CK), 80% chemical fertilizer + 20% liquid humic fertilizer (S1), 60% chemical fertilizer + 40% liquid humic fertilizer (S2), 60% chemical fertilizer + 20% liquid humic fertilizer (S3), and 40% chemical fertilizer + 40% liquid humic fertilizer (S4). Substituting chemical fertilizers with liquid humic fertilizers effectively enhanced the soil organic matter (SOM) content in the topsoil (0–20 cm) for all treatments. Compared to CK, the amounts of available N (NO3−-N and NH4+-N) were decreased in the topsoil and the amounts of total N, total phosphorous and available phosphorous were increased in the subsoil (20–40 cm) for all treatments. The β-diversity of bacterial communities exhibited the highest sensitivity to soil environmental changes, followed by that of archaea, whereas fungi demonstrated the least susceptibility. The higher soil carbon/nitrogen ratio and SOM content in S2 altered the abundance of microorganisms (Proteobacteria, Ascomycota, and Crenarchaeota) that were closely related to the decomposition and mineralization of SOM and N, enhancing the efficiency of SOM decomposition. The activities of sucrase (SUC), urease (UE), and phosphatase were increased, also promoting the conversion efficiency of SOM and improving N fixation and soil fertility. In the organic fertilizer substitution treatments (S1 and S2), the abundance of dominant Actinobacteriota, Ascomycota and Crenarchaeota phyla were increased, as well as the activities of SUC and UE, accelerating the decomposition and mineralization of SOM and improving soil fertility. In the top, organic fertilizer substitution combined with reduced chemical N fertilizer (S3 and S4) treatments increased the abundance of bacteria and fungi. In addition, RDA showed that total potassium content could significantly affect changes in the bacterial and fungal community structure in subsoil. Overall, organic fertilizer substitution enhanced the content of soil available nutrients and improved soil nutrient retention. It is recommended to promote organic fertilizer substitution + chemical N fertilizer reduction (S4) with the supplementation of potassium fertilizer in the subsoil. The findings provide a theoretical basis and practical guidance for improving orchard soil management and achieving sustainable development in the apple industry.

Ultisol as a marginal soil has become ‘a hope’ by farmers in Indonesia due to land use change, lately. However, the soil is susceptible to degradation since it has low soil aggregate stability (SAS) as affected by low soil organic matter (SOM) content. A pot trial about application of fresh organic matter (FOM) was aimed to improve SAS of Ultisols under wet tropical rainforest. Three types of FOM (Tithonia diversifolia, Chromolaena odorata, and Gliricidia sepium) at different size (8, 6, 4, 2, and 0.5 cm) were applied for 1% (20 g 2 kg-1 soil), then mixed and incubated for three months. The experimental units were allocated in a completely randomized design at a glasshouse. The results showed that FOM generally increased SOM content, percent aggregation, as well as SAS of the Ultisol. Among the organic matter (OM) sources, tithonia gave the highest SOM content after a 3-month incubation. Within the types of OM source, the smallest OM size applied showed the highest SOM content. Tithonia at 0.5 cm in size gave the highest SOM (3.47%) of the Ultisol and SAS increased by 68% compared to the initial soil. Overall, there was a positive correlation (R2 = 0.43) between SOM content and aggregate stability index, but no correlation (R2=0.04) between SOM content and percent aggregation of the Ultisols.[How to Cite : Yulnafatmawita and F Anggriani. 2013. Fresh Organic Matter Application to Improve Aggregate Stability of Ultisols under Wet Tropical Region. J Trop Soils 18 (1): 33-44. doi: 10.5400/jts.2013.18.1.33][Permalink/DOI: www.dx.doi.org/10.5400/jts.2013.18.1.33]

BackgroundCrop‐ and site‐specific quantification of non‐harvestable aboveground residues and root biomass is essential for predicting management‐induced changes in soil C storage.AimsThe aim of this study was to quantify stubble and root biomass C from productive grass–clover leys used for cutting as affected by fertilization and sward age.MethodsBased on an organic long‐term dairy crop rotations experiment with 4 years of grass–clover in a six‐course rotation, we examined the effects of fertilization (unfertilized and 300 kg total‐N ha−1 in cattle slurry) and sward age (1–4‐year‐old) on herbage yield and composition, stubble biomass, and composition and root biomass of grass–clover ley.ResultsLey duration and fertilization altered plant community composition and aboveground productivity but did not affect stubble and root biomass C.ConclusionsThe results question the use of yield‐dependent allometric functions for grass–clover ley used in simulation models and life cycle assessments for C accounting in agricultural systems. For predictions of soil C changes, we recommend the use of a fixed stubble‐derived C input from grass–clover ley regardless of sward age and fertilization‐induced differences in species composition, and herbage yield. Likewise, a fixed root‐derived C input for 1‐year‐old grass–clover, irrespective of fertilization, may be implemented. However, the contribution of continuous rhizodeposition and fine root turnover to root‐derived C input need to be accounted for.

This study presents the spatial variability and dynamics of soil organic carbon (SOC), soil organic matter (SOM) and soil pH contents at the Wonji Shoa Sugar Estate (WSSE), Ethiopia. Soil samples were collected immediately after the sugarcane was harvested and then analysed for SOC, SOM and pH content using standard procedures. The analysis results showed that the pH value varied between 6.7–8.4 (neutral to moderately alkaline) and 7.3–8.5 (neutral to strongly alkaline) for the top and bottom soil profiles, respectively. The SOM content is in the range of 1.1–6.7% and 0.74–3.3% for the upper and lower soil layers, respectively. Nearly 45% of the samples demonstrated a SOM content below the desirable threshold (&lt;2.1%) in the bottom layer and, hence, inadequate. Moreover, most of the topsoil layer (95%) has an SOM content exceeding the desirable limit and hence is categorized within the normal range. Interestingly, the SOC content showed a spatial variability in both the surface and sub-surface soil layers. A lower SOC and SOM content was found for the sub-soil in the south and southwestern part of the plantation. A further decline in the SOC and SOM content may face the estate if the current waterlogging condition continues in the future for a long period. Overall, the study result emphasizes the need to minimize the pre-harvest burning of sugarcane and action is needed to change the irrigation method to green harvesting to facilitate the SOC retention in the soil and minimize the greenhouse emission effect on the environment, hence improving soil quality in the long-term.

Soil nutrient status is the foundation of agricultural development. Exploring the features of soil nutrients and status evaluation can provide a reference for the development of modern agriculture. LightGBM is an optimization algorithm based on the boosting framework, which uses histograms to improve the accuracy of the model. Based on the construction of the LightGBM model, the main nutrient features and status of tobacco planting soil were analyzed in seven towns in Debao County, Guangxi Province, namely Yantong Town, Longguang Town, Najia Town, Zurong Town, Du’an Town, Dongling Town and Jingde Town. The confusion matrix results show the accuracy of the LightGBM model is 94.2%, and the eigenvalue analysis shows that the available potassium (K) contributes the most to the nutrient status. The pH value of soil ranging from 6.1 to 7.8 is favorable for tobacco growth, and the contents of soil organic matter, total nitrogen (N), available phosphorus (P), exchangeable calcium (Ca) and exchangeable magnesium (Mg) are at the appropriate level. Available potassium (K) and available zinc (Zn) are at a high level, but available boron (B) is slightly insufficient. The nutrient status of 10% of soil is at an extremely high level, and about 81.03% of soil is medium level or above. The LightGBM model has high reliability in the automatic evaluation of soil nutrient status, which not only can accurately monitor the soil nutrient status but also reflects the correlation and importance of nutrient factors. Therefore, the LightGBM model is significant for guiding soil cultivation and agricultural production.