Soils additive product effects

In addition to a complete water balance, EPIC estimates plant biomass production, fertilizer use, wind and water erosion, loss of nitrogen and phosphorus from the soil, and the effect of nutrient loss from the soil on plant growth. 

The increasing uses of industrial by-products as soil additives for pastures and forage crops, and their increasing cultivation on land exposed to actual and potential pollution, highlight the need for continual monitoring for Mo toxicity effects. Fortunately, the soil and plant concentrations of Mo that are diagnostic for toxicity are more precisely known than are those for Mo deficiency. 

The biomass production of millet grown in a soil that contained degraded wood (sawdust) compared with a synthetic reference (standardised culture substrate) was 67%. This could be expressed as 33% inhibition. However, the soil sample without any addition produced no more than 52% plant biomass compared with the standard substrate. In relation to the untreated soil, the net effect of the wood biodegradation should be seen as 129% biomass (67% instead of 52%), which is a positive effect and not inhibition. 

Biomass added to soil in the form of photosynthetically generated stalk or straw by-products of crop production has the effect of temporarily removing carbon dioxide from the atmosphere. Eventually, most of the biomass incorporated into soil decays and releases its carbon back to the atmosphere as carbon dioxide. However, biomass can be pyrolyzed to release volatile matter leaving a pure carbon residue called biochar. Biochar does not decay and the elemental carbon of which it is composed remains in soil. Biochar is being advocated as a soil additive that retains nutrients and water and sequesters within soil the carbon dioxide produced in the decay of plant matter. The volatile matter released in making biochar contains liquids and gases that can be used as fuel and as feedstocks for chemical synthesis. 

The dkect high temperature chlorination of propylene continues to be the primary route for the commercial production of aHyl chloride. The reaction results in aHyl chloride selectivities of 75—80% from propylene and about 75% from chlorine. Additionally, a significant by-product of this reaction, 1,3-dichloropropene, finds commercial use as an effective nematocide when used in soil fumigation. Overall efficiency of propylene and chlorine use thus is significantly increased. Remaining by-products include 1,2-dichloropropane, 2-chloropropene, and 2-chloropropane. 

Acrylamide polymers are used as multipurpose additives in the oil-producing industry. Introduction of polymers into drilling fluids-drilling muds improves the rheological properties of the fluids in question, positively affects the size of suspended particles, and adds to filterability of well preparation to operation. Another important function is soil structure formation, which imparts additional strength to the well walls. A positive effect is also observed in secondary oil production, where acrylamide polymers additives improve the mobility of aqueous brines injections, which contribute to... 

Biological effects and stimulation of plant growth induced by hydrogel additives are observed at doses which are often much lower than those obtained from purely physical evaluation. For example, it has been recently shown [13] that, according to various criteria of plant development, the SAH additives even at dosages of 50 to 140 kg ha-1 provide a productivity in sandy soils at the level obtainable by treatment with 20% (of the order of hundreds of tons per 1 ha) alluvial deposits. There seems to exist a mechanism allowing the plants to efficiently utilize small water reserves contained in the SAH particles. 

The ET cover cannot be tested at every landfill site so it is necessary to extrapolate the results from sites of known performance to specific landfill sites. The factors that affect the hydrologic design of ET covers encompass several scientific disciplines and there are numerous interactions between factors. As a consequence, a comprehensive computer model is needed to evaluate the ET cover for a site.48 The model should effectively incorporate soil, plant, and climate variables, and include their interactions and the resultant effect on hydrology and water balance. An important function of the model is to simulate the variability of performance in response to climate variability and to evaluate cover response to extreme events. Because the expected life of the cover is decades, possibly centuries, the model should be capable of estimating long-term performance. In addition to a complete water balance, the model should be capable of estimating long-term plant biomass production, need for fertilizer, wind and water erosion, and possible loss of primary plant nutrients from the ecosystem. 

Stored solid manures acts as a source of N20 production/consumption and emission. Covering heaped manure shows reduction in NH3 emissions but has no effect on N20 emission, while other studies showed that both were reduced. The addition of chopped straw reduced N20 emission by 32% from the small scale of cattle manure. [54], Slurry or liquid manure with no cover showed negligible N20 release, while slurry with straw cover might act as a source of emission [55]. N20 emission occurs following manure application to soil [56], Various factors that affect N20 release from soil include (i) type of manure, (ii) soil type, (iii) manure composition, (iv) measurement period, (v) timing of manure application, (vi) amount of manure applied, and (vii) method of application. 

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