Effects of biosolids on tobosagrass growth in the Chihuahuan desert

Abstract

Little information is available about seasonal application and carry-over effects of biosolids application to semi-arid grasslands. Biosolids rates of 0 (control), 7, 18, or 34 Mg ha-1 were topically applied to tobosagrass (Hilaria mutica (Buckl.) Benth.) experimental plots in a Chihuahuan desert grassland in western Texas. Biosolids were applied twice in 1994, for one-year-only, either in winter-and-summer (WS), or spring-and-summer (SS) seasons. Half of the plots were irrigated every summer for 4 years (1994-1997). Tobosagrass standing crop (herbage yield) and total Kjeldahl nitrogen concentration (plant %TKN) were measured every year during the 4 years of the study (1994-1997). An increase in biosolids rate increased tobosagrass herbage yield linearly during the 4 growing seasons. Linear and quadratic responses to biosolids rates were observed in %TKN during the experiment. Irrigation increased tobosagrass herbage yield. Irrigation decreased %TKN in 1995 and 1996 and had no influence during the other years. Winter-and-summer applications increased herbage yield more than spring and summer applications in 3 out of 4 years. Spring-and-summer applications increased %TKN more than winter and summer applications only in 1996. Carry-over effects on tobosagrass herbage yield and %TKN were observed in the second, third, and fourth growing seasons after biosolids application. Twice-a-year application of biosolids for 1-year-only offers an excellent means to improve tobosagrass productivity and forage quality.

Residual Effects of Biosolids Application on Forage Production of Semiarid Grassland in Jalisco, Mexico

“…rate in arid grasslands [11]. The lower forage production in New Mexico and Texas can be attributed to low precipitation in their study sites with 267 and 310 mm of mean annual precipitation and lower than average at three out of four years during the study.…”

“…Domestic, aerobic biosolids from the wastewater treatment plant at Aguascalientes city, Mexico, were applied one time only at 0 (control), 15 [20]; total nitrogen (Kjeldahl) [21]; phosphorus (Bray-1) [22]; potassium, calcium, and magnesium, extracted by ammonium acetate; aluminum, zinc, iron, copper, manganese, boron, lead, arsenic, chromium, and cadmium extracted by DTPA [23] and analyzed by Atomic Absorption Spectroscopy; sulfur was extracted with calcium chloride and determined by turbidimetric method and chloride by volumetric methods. Chemical analysis of biosolids (Table 1) showed that pH and electrical conductivity were lower, and organic matter, nitrogen, and phosphorus were slightly higher than values in other studies [10,11]. Because of their N and P contents, biosolids have the potential to improve soil fertility and promote plant growth at different agricultural scenarios.…”

“…Biosolids rates from 18 to 45 Mg ha −1 have been recommended for arid rangelands with good agronomic results in terms of grass forage production and soil fertility [13]. Also, residual effects have been observed on soil fertility [14][15][16] and on forage production of arid grasslands [10,11]. However, limited information is available on the residual effects of biosolids application in semiarid grasslands.…”

“…Several studies have shown that surface-applied biosolids promote grass production at arid and semiarid grasslands [10][11][12]. Biosolids rates from 18 to 45 Mg ha −1 have been recommended for arid rangelands with good agronomic results in terms of grass forage production and soil fertility [13].…”

Effect of Types of Biosolids and Cattle Manure on Desert Grass Growth

“…The beneficial use of biosolids as soil amendment and the enhancement of rangeland plant production have been documented (Fresquez et al 1990;Jurado and Wester 2001;Mata-Gonzá lez et al 2002, 2004. Biosolids, however, require certain quality standards to prevent contamination.…”