A Poultry Litter-Derived Organomineral Phosphate Fertilizer Has Higher Agronomic Effectiveness Than Conventional Phosphate Fertilizer Applied to Field-Grown Maize and Soybean

Inadequate disposal of poultry litter (PL) may promote eutrophication of water bodies due to its high nutrient content, including phosphorus (P). Thus, recycling P from PL to produce organomineral fertilizer (OMF), reduces the dependence on finite mineral P reserves, and also reduces P losses from soil. In this context, a field experiment was carried out to assess the agronomic effectiveness of a granular PL-derived OMF applied to maize and soybean in a highly weathered tropical soil. OMF was compared to single superphosphate (SSP) at five P rates between 0 and 70 kg ha−1. The shoot dry weight (SDW) and grain yields of soybean and maize were affected by P rates; however, no difference between OMF and SSP was found. A similar trend was observed for soil P and P uptake. The leaf P content and soil pH were not affected by either P sources or P rates. Although there was no difference between OMF and SSP on the crop yields, OMF had the highest relative agronomic effectiveness based on the SDW. These results show that the production of granular OMF from PL is a viable alternative to conventional P fertilizers and reduces the dependence of mineral P reserves.

Preparation and nutrient release kinetics of enriched biochar-based NPK fertilizers and agronomic effectiveness in direct seeded rice

In present study, two enriched biochar-based fertilizers were prepared having fertilizer grade of 6-6-4 N-P2O5-K2O by intercalation of NPK fertilizers mixture solution as EB-1 and additional humic acid and seaweed extract as EB-2. In laboratory, batch experiment were done to compare nutrients (NH4+, NO3−, P and K+) release patterns of developed fertilizers along with conventional fertilizers. Enriched biochar fertilizers (EB) demonstrated much slower release pattern of NH4+, P and K+, however NO3− release was similar over conventional fertilizers. The cumulative release of N in EB fertilizers was similar to conventional fertilizer, however significantly less of P and K were released during the period of 72 hrs. The field response study of enriched fertilizers EB-2 revealed 29.5, 11.5 and 22.9% higher apparent use efficiency than conventional fertilizer. The slow nutrients release behaviour of EB fertilizers implies reduced losses and enhanced NUE as reflected by higher apparent recovery of N, P and K.

Critical Evaluation of the Agronomic Effectiveness of Recovered Phosphate Fertilizer Produced From Incinerated Sewage Sludge Ash

Phosphorus (P) recovery from incinerated sewage sludge ash (ISSA) has been extensively investigated, and various recovered phosphate fertilizers (RPFs) have been produced. In this study, three RPFs (calcium phosphate compounds (CaP), struvite (SP), and P-loaded biochar (BP)) produced from ISSA were characterized and their agronomic effectiveness were verified by pot experiments with the cultivation of choy sum (Brassica campestris L. ssp. Chinensis var. utillis Tsen et Lee) and ryegrass (Lolium perenne L.). The SP has the highest P purity while the BP has the most complex P species. And the plant growth results showed that the RPFs greatly facilitated plant growth and demonstrated superior/comparable effects to those of MP/CoF. In general, choy sum fertilized with SP showed the best effect due to the Mg involved and the high P purity of SP, while ryegrass fertilized with BP performed the best among all of the groups because of the additional nutritional elements and the high P availability of BP. Additionally, the accumulation of heavy metals in the plants under all conditions did not exceed the limits stipulated in the regulations. These results indicate that recovering P from ISSA is an attractive technology to produce P fertilizers, which can alleviate both the scarcity of phosphate resources and the burden of ISSA management.

Recent Advances in the Use of Tithonia diversifolia Green Manure for Soil Fertility Management in Africa: A Review

Tithonia biomass transfer was presented as a technology that would replenish infertile soils, enhance food security and eradicate poverty in Africa in the 1990s. Since then, a huge volume of research has been conducted and the agronomic effectiveness of tithonia unequivocally demonstrated. Its reported effects on soil properties have however been inconsistent. This has made it difficult to develop a predictive understanding of the effects of tithonia on soil properties. Socio-economically, tithonia failed to live up to the hype on its ability to increase the farmers’ incomes. Adoption rates have been dismal mainly because of high labor costs associated with its use. Two decades later, poverty and food insecurity are still widespread in Africa despite the enormous research and extension efforts that were devoted to popularizing the technology.

Most Plant Nutrient Elements Are Retained by Biochar in Soil

Biochar may contain substantial amounts of plant nutrient elements, and at typical rates of application, may supply luxury levels of K, Ca, P, and other plant nutrients. However, little is known of the agronomic effectiveness of these nutrients because they exist in diverse compounds and are located in the microporous matrix of biochar particles. We have identified the compounds and location of nutrient elements in three biochars and observed their release from biochar particles in soil. Much K was quickly released from biochar but little or no Ca, Mg, S, and P were released over eight months, which represents a very different behavior from chemical fertilizers that are mostly water soluble. There is clearly a need to determine the availability to plant nutrients in biochar. Appropriate laboratory methods should be developed for measuring the availability of plant nutrients as standard methods of fertilizer analysis are ineffective.